Original subtitles

in this course I'm gonna teach you everything you need to know to get started programming in

python.

Python is one of the most popular programming languages out there,

and it's by far one of the most sought after for jobs

and so if you're trying to get a job

or you're trying to you know,

automate your life

or you try to write awesome scripts to do a bunch of different things than

python's for you

honestly

more and more developers every day are moving their projects over to python because it's such a powerful

and the surgeon

easy to use language,

a lot of programming languages out there just aren't very beginner friendly there's

a lot of syntax there's a lot of like little things that if you get wrong the program will yell at you.

python is the complete

opposite of that.

you basically just type out what you want to do in python does it it's that simple there's not

a whole lot of syntax to learn the learning curve is literally zero you jump in,

you can start writing your first program in seconds.

in this course

I'm gonna teach you guys.

everything you need to know to get started in python.

I designed this course

especially for python,

and each lesson has been specially designed with examples

that will help you along the way.

with so many people starting to learn python the question isn't,

why should you learn pipe on the question is why shouldn't you ?

and I think for a lot of people the reason they might not want to learn python is because they're intimidated or they're afraid that it's going to be too hard.

trust me I am going to hold your hand through this entire course we're going to talk about all the core concepts in python we're going to look at

everything you need to know

to start programming in python and start being confidence are writing scripts and start writing programs that are awesome in doing cool things in your life.

anyway

I'm super pumped to be teaching you guys python.

I can't wait to get started in this course

and I hope you guys stick around and fall along with the course and learn this amazing programming language

in this tutorial dominates three guys how to install python onto your computer.

and we're also going to install a text editor that we can use to write

our python programs

in.

so the first order of business is to actually install

python on your computer.

so we want to do is head over to your web browser

and

you want to go over here to this page it's just

www dot python dot org

forward slash

downloads

and on this

page there's

going to be

two buttons down here

and this is going to say download python three point six point three.

and at least

the version that I have right now or download python two point seven point one four.

so here's the thing about python there's actually two major versions of python

that are in use

currently

there is

python two

and there's python theories you can see over here,

this is like two point seven point one four

basically any python two

version we would just refer to as like python two

and here's like the latest

python three version.

and so there's these two versions that you can download and the first thing we have to decide on which version do we want to download.

and here's the basic difference

python

two

is a legacy version of python which basically means that

it's like an

old version and it's not being like actively maintained or supported

like officially by python anymore.

python

three is like the future of python it's like the newest version it's the one that's getting actively maintained and supported.

so there's pros and cons to picking either won

a lot of people say like python too

has been around longer and so there's more like

libraries there's basically just more python code written in python two

so therefore like there's a few more things that you can do in pipe onto then you can do in python three

but then again

python two is not supported and you know,

five or ten years from now

probably no one's going to be using it.

python three it like a site is like the future of python it's the newest version it's the one that

you know it's sort of being maintained going forward.

so for the purposes of this tutorial I'm going to be teaching you guys

python

three

so we're going to want to download python

three

now here's vaguely

if you learn python three or you learn python to the differences aren't very big.

there are a few differences in like some syntax and just so

you know little things here and there,

but if you learn python three you'll be able to jump right in and

code in python two as well don't let anyone

tell you that

you have to learn one of the other.

we're going to learn python three just because it's I think probably the best for a beginner to learn.

and so that's the one that we want to download so I'm just going to click download python three

and we're gonna go ahead and download

this version.

and when that's done downloading I'm going to head down to my downloads folder

and you'll see here we just have this file

doubleclick,

and we get this like python installer so I'm going to click through here,

and we'll be able to install python three on our computer

right when that's done and stalling we can just close out of this and we should begin to get us now we have python three

installed on our computer.

the next step

is we need to choose a text

editor so

we're going to be writing a bunch of code so we're going to need some you know environment of some program that we can write all that code in.

and really you can write python in any text editor you could write it in like a note pad or tax at it,

it doesn't really matter

but there are special

text editors that are designed

just for writing python code.

and these are called

id ease and not stands for

integrated development environment.

it's basically just a special environment where we can you know ron and execute our python code.

and it'll you know basically like tell us how we're doing so were

the only if we write something that's wrong or we

have errors it'll kind of

point us in the right direction of what we need to do to fix that stuff,

so in this course we're going to be using an idea

and

one of my favorites

and one of the most popular ity ease for python is called pi charm.

so I'm over here on this website.

it's called

jet brains

dotcom

forward slash

pi charm.

and this is the idea that we're gonna be using in this course

so I'm just gonna come over here and click this big download

now button

and we'll go ahead and

download this

pie charm program

right so I'm getting this page are here you can see there's two versions of pi charm

one as a professional version and that one's like paid they have to pay for it.

but then there's this community version down here and that's free and open source so I'm going to download this one

and this should have everything we need to get started using python

right when that finishes downloading I'm just going to

pull that up in my downloads folder

and

again we can just sort of

run this guy

and I'm on a mac so I'm going to have to drag it over to my applications folder.

all right so now have pi charm

and we have python

three installed on your computer.

so we're ready to start programming in

python.

in this tutorial we're going to create our first

python program.

and we're going to be able to run it and

see how everything works.

the first thing I want to do is open up

pi charm so pi charm was the

idea he the

integrated development environment

that we downloaded in the last tutorial so

I'm just going to go out and search for it on my computer

and I can just open it up

and we first opened up high charm we should basically just get a window

prompting us to create a project.

so you can see that down here.

actually the first thing I want to do though is come over here to configure

and I'm just going to

click on preferences.

and I actually want to

change the appearance

so

I'm gonna go ahead and

give this a theme so I just went over here to appearance and behavior appearance

and I'm gonna change the theme to

darker color

because I think it's a little bit easier to

use and look at,

but you don't have to do that if you don't want you

so

down here

I'm just going to click

create new projects

and it's going to

give us this little window right here so I can just name my project.

and I'm just going to name this

graph.

and then there's other option down here where it says interpreter.

now

what we wanna select

is

python version three

so if I click down here you'll notice that there's a couple different options.

so I'm on a mac computer

and

by default mac has

python

version two installed on it.

if you're on a windows machine I'm not sure if it does but

in this tutorial we're going to be using python three so you wanna make sure that you have python

three selected as the interpreter,

otherwise

you

might not be able to fully follow along with what we're doing in this video.

so now it's going to come down here and click

create.

and this is going to go ahead and create our projects

for us

right so now we have

our

python project

up and running,

and I'm sure you guys how we can create our first

python program,

so over here in this draft folder and this is just that project that we created.

I'm just going to right click

and I'm saying new

and I'm going to come down and click

python file so we want to create a new python file this will be our first

python program.

and

I can just give this a name,

so why don't we just call this

app

and it's going to click ok

all right so now we have our first

python file

open

and we can just start typing in some python so I want to show you guys.

does a very basic python program.

and this is just going to be a hello world programs so we're just gonna print something out onto the screen.

so when I say

what I want to do is I want to type out p r iyer anti prince

and wanted to have an

open and closed

parentheses

now

inside of those parentheses we can make some

quotation marks

and inside of the quotation marks I'm just going to tape out

hello

world.

so this is like a very basic python program.

and what this is gonna do is

it's just going to print out hello world

onto the screen.

and so now what I can do

is I can actually run this file and we're actually getting a little arrow here it wants us to create a new line

at the end of the file.

and so now in order to run our python program I'm just going to come up here to the top

and I'm cinematic run

and we'll click this run button right here

and I will see what happens

so it's

asking me what I want to run I can just click add up

and

down here at the bottom you'll notice that we have this text that just got printed out

hello world,

so

whatever I

print

or whatever I put inside of this print statement is going to get printed out

down below in the council so

as long as you're getting that print statements work then you

actually written your first python program.

and as we go through it

forward in the course were can be writing

all sorts of awesome python programs.

and we're going to do an

all sorts of cool stuff

in this tutorial I wanna talk to you about writing a basic python programs so we're going to write it as a very simple python program.

we're going to look at how we can go ahead and write up programs we're going to talk about

how our programs are getting executed by python

and we're also going to draw out a little shape onto the screen so

this is going to be pretty cool I'm excited to

talk you guys about just the

bare basics of python,

and really just sort of give you an introduction so

over here

we have our

basic text editor and so

any of the

python code that I write inside of this file

is actually going to get executed by a python so

this python file

has a bunch of

python code inside of it.

and basically what we're doing when we're

programming in python is we're just giving the computer a set of instructions.

right that's really what programming is it's just like we're specifying a set of instructions

and the computer is going to go off and execute those instructions that we give it.

and so

the more complex the instructions we give to the computer the more complex

the tasks

the computer can

carry up.

so I'll show you guys how we can use some python instructions or some python code

in order to draw out a shape onto the screen so

I'm actually going to draw out

a little triangle.

so over here,

we can actually print something out onto the

screen and python using something called a print statement so I can just type out

print.

and inside of these parentheses.

I can just type

some quotation marks

and inside the quotation marks

we can

put whatever we want to print out onto the screen.

so I'm gonna

copy this and I'm actually going to make

a few of these little prince statements

and we're going actually draw a sheep.

so

we're gonna draw like

a triangle type shape

so down here it's gonna draw a forward slash

and then up here I'll make a space and we'll do another foreign sash

here will make

two spaces

with united forward slash.

and over here

we can make three spaces and afford sash.

and now I'm going to draw like a vertical bar is going all the way down.

and actually we can do some underscores here as well.

I think high school

right so now we have our triangle looking shave and you can see

it looks kind of like a right triangle

so I can save my file.

and I can either come up here to run and

click run app

or of using pie charm you can also just come over here and click this play button

and when I click the play button I want you to notice what happens down here

so

down here we have this little window and

this is called the consul

and it basically the council is a place where python is going to

output some information so

when we use this print statement were basically telling python late

hey can you print something out onto the consul.

so

there's a lot of situations where we're gonna wanna see what's going on in our code.

and we can use that print statement and

print things out to the council.

and we can basically like have a little window into what our programs doing

in our case we're just going to be printing out this triangle onto the consul.

so I'm gonna come over here and click this play button

and you'll see down here

we're actually printing out that

triangle

so mission accomplished we were able to print out our shape.

so I can really draw any shape I want it as long as I was

able to

specify

inside of these print statements.

so

essentially what python's doing when I click that play button

is it's going into this file and it's looking at all of these instructions in order.

so the first thing it does is it goes to this instruction and it says

ok,

they want me to draw out these like little forward slash in this vertical bar onto the strain,

once it does that it goes down to this instruction it says

ok

they want me to print something on again

when it prints dot out it goes down to this instruction

etc

so

python is actually going to execute the lines of code that we write

in order.

so

the order in which I write the instructions

matters a lot.

so for example if I was to take this last line here

and put it up here at the top.

now when I save the file.

instead of just drawing up that triangle.

it's going to draw out

this little upside down

bottom thing at the top and then

the rest of the triangle down here so

the order of the instructions actually matters a lot.

so this is basically how your python programs are going to go.

as we go through this course we're going to learn more and more of these little lines so here we're just using this little print function basically and just print something out on to the screen,

there's a bunch of little things like this that we can learn as we go through

will learn more and more instructions that we can give to the computer.

but in this lesson I just wanted to kind of show you guys the basics right.

oh

we can essentially just define these little instructions for the computer

and the computer will execute them

in order.

and this tutorial I wanna talk to you guys about using variables in

python.

now in python and you're going to be dealing with

a lot of data

and so a lot of times in our program we're going to be working with

all types of information and data and values,

and sometimes that data

can be difficult to manage.

so in python we have this thing called a variable.

and it's basically just a container

where we can store certain

data values.

and when we use a variable when we put those

data values inside containers.

it makes it a lot

easier for us to work with and manage

all of the different

data inside of our programs.

so variables are extremely helpful and it's sort of like a

core topic in

python that you're really going to want to know and master.

so in this tutorial omelets each you guys.

everything you need to know to get started with variables we're going to look at what they are

why they're useful and we'll look at the different types of variables

and the different types of

data that we can store

inside of variables,

who over here in my

python file I just have a very simple program.

and it's basically just printing some text out onto the screen.

and so this is actually a little story that I wrote it says.

there once was a man named george

he was seventy years old.

he really liked the name george

but didn't like being seventy.

so this is a valid python program I can go ahead and

run this program

and you'll see down here in the council

everything prints out and

it looks great so

we have an awesome little python program here.

well let's say that inside of our story I wanted to change

the character's name

so instead of naming the character george let's say I wanted to name the character

jon

well

I'm going to have to go through and I'm going to have to manually change the name george to the name john at every place inside of this story where it's mentioned.

so I'm not to go over here and I'll say

ok

john I'm going to have to manually change that

and then

ok it's out here we're going up to again manually type in john and change it to john.

so in order to change the character's name I had to manually go in and change it in both places.

and now let's say

ok

maybe we want to change the characters ne

age also so in addition to changing the name.

we also want to change the age let's make him a little bit younger so why don't we say john is going to be thirty five.

so you see here I had to come here and manually change the age and then come down here

and manually change it again

right.

and now that we changed it like

it's going to work it's going to be updated in our program.

but you'll notice that in order to make that change like I had to look through the entire program find it where that

value was and change it,

and

this was only with

four lines

of the story imagine if I had a story that was like

thousands of lines long.

and we mentioned that the character's name and

age like

hundreds of times.

we don't have to look through each one of those lines and

manually change the character's name

and that is not a very good way for us to do this

and

it's really not a good way for us to manage the data in our program right the

character's name in the age.

and so we can actually use a variable

in order to store

the character's name and the characters.

age.

and when we use that variable it'll make it a lot

easier for us to put the character's name and age.

inside of our little program here.

so I'm gonna show you guys how we can create a variable for the character's name and age.

now it's going to go up here above this print statement.

and

up here I want to create a variable.

so when we create a variable in

python we actually need to give

python

a couple pieces of information.

the first piece of information we need to give python is the name of the variable so I need to actually assign a name

to this container where we're going to be storing information.

so all I have to do is just type out

the name of the variable

that I want to create so I'm going to create a

variable called character name.

so I'm just going to say

character

adam's they underscore

name

so generally when you're creating a name

for a variable in python.

you want to separate different words

with an underscore so I have two words here and I'm separating them with an underscore.

and now what I need to do is I need to

put a value

inside of this very more so

basically what I can do is I can just say

equals

and over here I can type a value

so I'm just gonna type out the character's name inside of

quotation marks.

so we're just gonna type out john.

so now we have a variable for the character's name

and below this character named variable I want to create another variable called

character

age certain just going to tape out

character

underscore

age.

and I'm going to set this

equal to the characters age which is thirty five.

so we now have two variables,

one representing the character's name and one representing the characters

age.

so what I can do now as I can replace

the character's name inside of this story

with

this variable.

and I'm gonna show you guys how to do that

so if we want to put a variable inside of this print statement.

I'm actually going to have to do a couple of things.

the first thing I'm going to have to do is

end off this

text in here so I'm going to have to put

a

quotation marks here the end

and you can see I'm basically

wrapping this whole thing into a

single like quoted line.

and now I also have this tax overhear the end so I'm going to have to put a quotation mark here.

so now I have

a

bunch of tax year in quotation marks.

and then I also have tax over here in quotation marks

now inside of here

instead of

saying the character's name

I want to refer to that character name

variable

so I'm just going to say plus

character

underscore name

and I want to say another plus sign so I basically I'm saying I want to

print out all of this text,

plus

the value that stored inside of character name

plus

all of this text.

and what this will do is they will actually print out the character's name we print this

so I'm gonna go ahead and run this program

and you'll see down here

and actually let me put a space over here,

and we'll run it again.

so you can see down here,

we still are printing out there once was a man named

john.

and so what python is doing is when it executes this line of code

it's coming over here and it's seeing

ok they want to turn out.

the value inside of character name

so it

python's going to go up here it's going to get the value,

and it's going to

insert it inside of there

so I can basically do this for every instance of the character name in my file so I can

you know

r is copy this guy right here

and

I can just paste it down here where the characters name is

so apace this

and you can see now were doing exactly the same thing that we did up there.

I can also do this for the characters

age someone to come down here

and I'll paste in what we just paste it in.

and I'm going to change this instead of character name was changed to character

age.

and I'm going to do this

in one more spots are going to do this over here we're mentioning the age

and again I'll just change this to

carry

your age.

and so now when I run this program it's going to print out the same story they were printing out before,

but

now I don't actually have to type in the character's name and the characters age.

I can just refer to this

variable.

and the cool thing about variables as if I wanted to change the character's name.

now all I have to do is change it up here so I could change the characters names you like

tom or something.

and we could also change their age so I could change

the age to be like fifty

and now that's going to automatically update throughout our entire story

when I click this play button you'll see

now we're using the name tom

and he's fifty years old.

so that's where variables can come in handy and

this can be a really awesome way to control and manage

the data that's inside of our programs

with variables you can also

modify their values

so

for example let's say that halfway through the story I wanted to change the character's name

why can just make some new lines over here,

and down here

I can actually assign a new

value to one of these variables.

so I can say like

character

underscore name,

and in order to give it a different value all I have to do is just say equals

and will give it a different value and so

let's say halfway through the story we want to change the character's name to mike

one now when I run my program

you'll see here in the first part of the story it says

there once was a man named

tom.

and in the second part of the story,

it's referring to the name as

mike.

so I actually

updated the variable

inside of my program

over here

and that's a really awesome way

you know a lot of times in these programs you're going to want to be modifying the values of variables

so you can do it

just like that.

and so finally I want to talk to you guys about the different

types of data that we can store inside of these variables.

so over here

I have the character name and character age

and

I'm actually storing what are called strings,

so a string is basically just

plain tax straight

so the name tom that's just plain text

down here these guys are strings as well.

so there's a data type in python,

called a string and it's just

basically going to store

plain text

so

you know any text that you would have like in a story early know someone's name

you can store inside of a string.

there's also another type of data

that we can store inside of python

which is numbers

so an additional storing text we can also store

numbers.

so if I wanted to start a number for example

let's say we wanted to store the character age instead of inside of a string.

we can store it inside of a number so

I could just type out fifty.

and when we're storing a number we don't need these quotation marks

you only need that quotation mark

when you're storing a string so if I wanted to a number I can just

write it out like this,

and in addition to using whole numbers I can also use decimal numbers.

so I could say like fifty point five six seven eight

to one three

and pythons are going to be able to store

that number as well.

you can store all different types of numbers

and we can also store

what's called a boolean value

and a boolean value is essentially a true or false value.

and there's a lot of instances in programming where we're going to want to represent

true or false

data

for example I can have a variable called like

his mail

and this would tell me whether or not someone was a male,

and in my case it will be true because I'm a guy right so I can

actually this needs to be

capital

so

I could sort of value of either true

or

false.

and actually if we were naming this in python

we want to use an underscore or so I would say

is underscore mail

and this can be either true or false

so

true or false values is maybe not something that you're used to dealing with like in the real world

but

in programming we're going to be using a true or false values

all the time they're super important so

like I said there's three basic types of data that we can work with in python there's

strings which is just like a plain text,

numbers which would be like either decimal numbers or whole numbers like this,

and there's true or false

values.

and these are the basic types of data I mean there's a bunch of other types of data that we can use but I would say ninety nine percent of the time.

as a new user

in a new programmer to python,

you're just going to be dealing with these

three types of data

so

those are the basics

of the data

and

also with variables

and you're going to be using variables

all the time in python so you definitely want to practice up and get comfortable

using them

in this tutorial are talks you guys about working with strings in python.

now what the most common types of

data that we're going to be working with in python is going to be strings

and strings are basically just

plain text so any text

that we want to have inside of our program

we can store inside of a string.

so I wanna talk to you guys about all the cool things we can do with strings and we're basically just going to get a

full introduction into why strings are awesome.

so over here,

I'm just going to actually print out

a strings I'm just going to say print

and

inside of these parentheses.

I can type out a string

in order to create a string I need to use quotation marks so I can make an

open and close quotation marks

just like that

now

inside

the quotation mark I can put whatever text

I want the string to have so we could say like

draff

academy.

and so now we have a string

with the text

draff academy inside of it

so if I run my program.

now down here we're going to print out draff academy as you can see,

and when we have these strings there's actually a bunch of cool things that we can do with them so

one thing I could do would be to create a new line inside of the string so if I wanted I could come over here,

and I could save backslash

n

and you can see it got highlighted in a different color.

and what this is gonna do is it's actually going to insert a new line into the string so now it's going to say draff on one line

and academy on another line.

so I'm gonna click play.

and you'll see down here we just get draff academy,

an addition to the backslash

n

I could also use

a backslash

quotation marks so

if I wanted to put a quotation mark inside of my string.

I can't just put a quotation mark like that

because pythons going to think that I'm trying to end

this strength.

so if I want to include a quotation mark I can just use this

special backslash character

and that's called the escape character and it

basically just tells python that

whatever character comes after it we want to

render a literally so

when I say backslash

quotation mark.

it basically means like

hey python

I want to point out a quotation mark.

and so now we'll be able to print

out

a quotation mark

right there.

I can also use this to print out of backslash so if I needed to put out a backslash.

I could see backslash,

and

it'll just print out a normal backslash now

so you can see just like that so

if you want and you can use that backslash to make

new lines or pronounce quotation marks,

or you can just use it as a normal

backslash

in addition to just typing out a string here I could also create a string

variable.

so I could come down here

up here and we can create a variable and let's call it

phrase.

and I'm going to set it

equal to

drop off a colony,

so I can

store this string value inside of a variable called phrase

and then when I want to print

out that variable,

or I want to access that string variable.

I can just

type the name of

the variable.

and you'll see that it's going to print out the value that was stored inside of it.

I can also use something called concatenation

and concatenation is basically the process of taking a string and

appending another string onto it.

so I could come over here and I could say phrase,

and I can say

plus.

and now I can add in another string so I could say like

is cool.

and now this is going to say

druff academy

is

cool,

so I'm basically appending another string

onto another one they call that concatenation.

and so in addition to doing all that stuff we can also use a special thing is called

functions

and a function is basically just a little block of code that we can run

and it will perform a specific

operation for us,

so we can use functions to modify our strings.

we can also use functions to get information about our strings.

so

I'm gonna show you guys a couple common functions we can use with the strings.

and

they're actually going to do awesome stuff so

in order to access one of these functions I can just say phrase and then I can say

dot.

and

I'm gonna show you guys a function that we can use to convert this

string entirely into lowercase so I could just say phrase dot lower.

and I'm going to want to type an

open and close parentheses,

and this will take this phrase,

it'll take my string and it will convert it to lower case.

so you can see now we just have a draft academy done here but it's entirely in lower case.

I could also do the same thing for upper case so I could say phrase dot

upper

and this will convert the entire string into

upper case so you can see now it's

entirely upper case.

so in addition to

converting the string into upper case

lower case

I can also

check to see if a string is entirely upper case are entirely lowercase.

so for example I could say phrase dot

is upper.

and this is going to give me back a true or false value

so it's going to be true

if the string is entirely upper case

or false

if it's not.

and you can see here we're getting a false value because this

is an

upper case

I can also use these functions in combination with each other so for example,

I could say phrase

dot

upper

and that a

parentheses

and then after this I can say

dot

is upper

and now what it's going to do is it's going to run this

upper function,

it's going to convert it into upper case.

and then it's going to run this

is upper function right after that

and you'll see now we're going to get a true value back because it will have converted the whole thing into upper case.

so you can see now we're getting a true value so

the news these functions

one after another it can be really useful.

and there's a few other ones that I want to show you so we can also

figure out the length

of

this string so

if I wanted to figure out how many characters were inside of this

string I could just say

l e n

and I'm actually going to make an

open parentheses,

and I'm going to make a close parentheses.

so I'm essentially saying

alien and this is another function it's the length function.

and inside of this alien function I'm actually passing

this

phrase variable

basically giving the length function this and it's going to spit out a number so tell me how many

characters are inside of this string.

as you can see here we get fifteen because there's fifteen characters inside of draff academy.

so that's how you can get the whole length of the string and that's going to be really useful as we go forward in python.

we can also get

individual characters inside of a string so

imagine if I wanted to just grab one of these characters like imagine if I wanted to

figure out what the first character in the string is

we're going to actually use

and open a closed

square bracket

just like that.

and in here I can specify the

index of the character that I want to graph.

so if I wanted to grab the first character in the string

I can put in a zero.

so if I say phrase

square bracket zero,

this is going to give me that capital g

and you can see down here

that's what gets printed out.

now I want to point something out

in

python.

when we're working with strings.

a string

gets indexed

starting with zero.

so you'll notice that in order to access this g.

I had to put a zero in here.

that's because in python.

when we use indexes on a string we start with zero

so if python is counting the characters

or its indexing the characters in a string it's going to start with zero so it's going to say

g is zero

I as one are as to

a history.

so we would say that g is at position

zero in the string.

I is at position one

r is at position two

a's at position three etc.

so we start counting

at zero.

so if I wanted to access

the first

character in the string.

this g I have to say phrase

zero and that's just a special thing

in python and actually most programming languages

do that so they'll start with

zero.

so for example if I wanted to access this

ei,

I'm going to have to put

zero

one

two three so I put three inside of here

now will be able to access that first

a.

as you can see we get an

a right here,

so this

is actually really useful being able to grab a specific character inside of a string

and you're gonna be using it

that a lot as we go forward and python

is also another really awesome function that we can use and it's called the

index function.

and basically what the index function will do is it'll tell us

where a specific

character or string is located

inside of our strings like unsafe phrase

dot

index.

and

I can actually give this a value so sometimes when we use these functions in python,

we can actually give them information so I can give this

of value

and we would call this passing a parameter so

I would call a value that I would give to a function

a parameter and you'll hear that word a lot.

so

for example I can say inside of here

capitol g,

and now this is going to return

the index

of

the capitol g inside of our string

so it should give us back

a zero because g is at the zero of index

and you'll see down here that we get a zero because that's where g is.

so for example if I put in

a inside it here like the lower case

a

it should give me zero one two three

because that's where the first

aid is inside of this string,

so I can click the play button

and you'll see it's giving us

a three.

you can also put actual words in here so for example I could put like

academy in here,

or I could even just put like

a c a d.

and this is going to tell me where this starts

inside of my string so when I click play,

it's going to give me an

a

because

that's where

a cat and he starts right

zero one two three four five six seven

eight

if I put something in here that wasn't in the strings of for example if I put a z in here,

that's not in here.

it's actually going to throw an error so when I play this you'll see that we get this error down here

because

the z is not found inside of our program so

that the next function again can be really useful we'll be using that a lot.

there's also one more than I want to show you which

is called replace

so we can say phrase not replace

and in here I can actually give this

two parameters so I can give this replace function

two values that it can use.

and the first thing I want to you

to give it is what I want to replace so for example I could say

giraffe.

and then I'm going to put a comma in here,

and I want to put in here what I want to replace

draft with so I could just say like

elephant

and now instead of saying draff academy this is going to print out

elephant academy.

so you can see down here it just says elephant academy so

this replace

function

can be

really awesome because we can replace

certain

words or even certain letters

inside of our springs with

other ones.

so those are some basic ways that we can work with strings inside of python

and

there's a lot of these different functions that we can use with strings.

these are some of the most common the ones that I just showed you right now,

but if you just do a google search you can find all sorts of

python functions that you can try out in use and you know,

see what they do,

but you definitely want to get comfortable working with strings and python because you're going to be working with them

a lot.

in this tutorial I wanna talk to you about working with numbers in

python

and numbers are one most

common data types in python and

any python program you write is most likely going to be dealing with numbers at

some point

so

I want to talk to you guys about the basics of using numbers we can talk about the different types of numbers that we can represent in python.

and I also want to show you guys some

awesome functions that we can use with number so we can do a certain like mathematical operations mechanism

awesome things

with numbers I'm going to show you guys

all of that in this video it's gonna be awesome so

first thing we can do is

we can actually just like print out a number.

so if I want to write a number in python it's really easy I basically just write the number so I could say like print

too.

and this is just going to print the number two out onto the screen,

so I can use a whole number like this I could also use a decimal number so I can say like two point

oh nine eight seven

and pythons are gonna be just fine with that we'll be able to print that on

the screen as well.

I can also make numbers

negative so I could make this

two point

oh nine

eight seven

a negative number and

python to be able to handle that just fine too.

in python we can also use

basic arithmetic so I could do things like addition subtraction multiplication

fancy like

three

plus four

and now this is going to print this out or was he like three plus

four point five.

and this will be able to print out the answer so we get seven point five.

and we can do a dish in we can do subtraction.

we can do division

or we could do like multiplication as well so you can

pretty much do whatever you want inside of python,

and if you want to make more complex mathematical equations we can also use

things to specify order of operations

so I could use parentheses.

so for example if I said three times four plus five

what python is gonna do is it's gonna multiply three and four together so it's going to be twelve and then we'll add five to that so we should get seventeen.

but let's say that we wanted to change up the order

right

I could actually put a parentheses around four and five

and now

it's going to add them first social ad foreign fighters will get nine and will multiply that times three so we should end up with twenty seven,

so you can see we can use those parentheses to specify order of operations so I could make like a very complex

little equation here and just by using numbers and parentheses.

we can also

use one other operation which is called the modulates operator so I could say like

ted,

and use this percent sign

three and this is actually read

ten

mod

three

and basically what this is gonna do is it's going to take the first number

divided by the second number,

and it's going to spit out the remainder.

so it's basically going to say

ok

ten divided by three.

that's going to be three

with a remainder of one.

so this is going to give us the remainder.

and

you'll see down here we get one because

that's the remainder of ten divided by three

that modulates operator can come in handy quite a bit.

we can also store these

numbers inside of variables

so we can store them inside of these

variable containers,

so I could

come over here

and I could create a variable called like

my underscored gnome

and we'll just store a value

of let's say like five and here

is why have you come down here and I can just print out my underscore numb.

and we'll be able to print that number out to the screen

just fine.

so in addition to doing things like a basic arithmetic

we can also

do some other stuff so one thing I could do is I could actually convert this number into a string.

so if I wanted to convert this number into a string I can just say s t r

and I can put the number that I want to convert

inside of these parentheses.

and so what's going to happen now is this number is going to be converted

into

a strings when I click

the run button you'll see it's

just printing out five but now instead of being a number this is actually a string.

and this is going to come in handy when you want to print out numbers alongside

strings,

so I can come over here and I can say like

my

favorite number,

and we'll be able to print this

number along with this

string so I click play,

and it's as five my favorite number,

if I was to get rid of this

string

right here

and I wasn't converting the number into a string.

now pythons gonna have a problem with this.

it's not going to allow us to do that you can see we get an

error so

anytime you want to print out a number

next to a string you gotta make sure that you use that little string function.

so

there's a bunch of other stuff that we can do with numbers and

a lot of times in python

you're gonna want to be using specific

metabolic more advanced math operator so

there's a bunch of different math

functions that we can use on our numbers

and a function is basically just like a little collection of code that does something so

a function could perform an operation like a mathematical operation on our number,

we can also give us information about our number,

so I'm sure you guys some of the most common functions that you'll be using in python

related to numbers.

the first one is called

abs

and it stands for absolute value so we can get the absolute value

of

a number.

and so over here I'm going to

make this variable negative five

and basically I can just say

abs

and I can make an

open enclosing parentheses over here,

and this is going to give me the absolute value of

this number up here,

so when I click the play button,

you'll see it's just giving us five because five is the absolute value of negative five,

I can use a few other functions there is another one

which is called

pau at so it says p o w

and I'm actually not going to use this variable we just as a normal number

and

this function is going to allow us to pass it

to pieces of information so I can give this function

two pieces of information.

the first is going to be

like a number.

and the second is going to be the power that I want to take that number two so I could say like three

comma

two

and this is basically just going to be

three

raised to the power of two,

so

it's just going to be three squared so we should get nine down here,

you can see that we do,

so I could pass in like

you know

some crazy number like

we could pass in a four

and we can raise it to the power of six,

and so we should get like a pretty big number here

and you can see we get four thousand ninety six so

this

power function is really useful for taking numbers to specific

powers.

so in addition to using this power function we can also use another function which is called

max.

so I can say max.

and what this is gonna do is it's basically gonna return

the larger of the two numbers that we pass into it

so right now I'm giving this

a four and a six

and this should tell us which number is higher

so over here it's just pulling out six because that's the bigger number.

I cannot see is another function called

men and this is going to do the opposite so now instead of printing out the max number it's going to print out the smallest number.

and it's going to turn out for down here as you can see.

another cool function is called the round function

and this is going to allow us to round a number so it's just going to follow like standard rounding rules.

so if I said like three point to inside of here

now is going around it

down to just normal three

but if I said like three point seven.

it's going to round it up to four so that'll allow you to round a number.

so there's a few other functions that I want to show you guys but in order to

get access to them I'm actually going to have to do something called

importing

and in python we can actually

import

external code

into our files and so if I want to access these

specific

math functions.

I have to import something called python math

so I can just say from

up here math

import

and this star and basically what this is gonna do is it's going to

go out and it's going to grab

a bunch of different math functions that we can use so

I already showed you guys a few of the zipper math functions but there's actually a bunch more.

and in order to access them we're going to need to include this line of code inside of our file.

so once we have that now I can access a few other so

is another function which is called the floor method and it's just

f l o r

and what this will do is it'll basically just grab

the

lowest number so it's essentially just going to chop off this decimal point.

and you can see over here now

we get a three because we're using that floor function.

there's also another one called

seal.

and that's just going to do the exact opposite so that's just going around the number up

no matter what so

no matter what will always get for

which we have a three point whatever here

and there's another one which is called square root so it's just asking you our team

and essentially this is just going to return the square root of a number so I can say like

thirty six.

and now we should get six back.

so

those are also very interesting functions and

inside of this

math module so we would call this a module and you don't have to worry too much about what that is right now,

just know that when we put this line of code into our program

it gives us access to a lot more

math

function so though

it basically allows us to do a lot more things with math

inside of our program

and there's a bunch of different math functions

in python and if you why you can basically just go online and search for different math functions.

I showed you guys a few here and I would say the ones that we looked at here are

probably the most commonly used but there's a bunch more.

and

like I said you know there's

tons of documentation on all this stuff so you can just look up

your math functions in

python and there's going to be tons and tons like lists of these things

that you can use inside of your programs to perform different math

operations,

but for now that has been a little bit of by using numbers a little bit about doing it on certain math operations and using functions

with those numbers

in this tutorial I'm going to show you how to get

input from the user.

so we're basically going to allow a user to

input information into our program.

and I'm actually going to take the information that the user inputs.

I'm gonna store it

inside of a variable and then we're going to be able to do something with

that variable.

so I want to show you guys how we can actually go about getting

input from someone.

and down here in my python file.

all I have to do to get input from someone is I just have to type out

input

and then an open and closed

parentheses.

and what this is basically going to do is it's going to tell python like

hey we want to get

input from

a user in python will

allow the user to

type in some information

and inside of these parentheses we can actually type

a prompt

and so generally when we want the user to enter in some information

we want to tell them what we want them

to enter.

and that's what we can put inside of here so I'm just going to say.

enter your

name,

so we're actually going to create a little python app,

which is going to allow the user to enter in their name

and then will store the name inside of a variable and then we'll basically just

say hi to the user so we'll say like high

and then whatever the name they entered was

so what I want to do is I actually wanna store

whatever the user and put it into our program

inside of a variable.

so I can actually go over here and I can create a variable I could just call it name

and I could set this variable

equal to

input.

so what I'm doing now is I'm taking the value that the user inputs

and I'm

storing it inside of this

variable container called

name

and so now

I have access to whatever they entered it.

so what we can do is we can say

print

and inside of the

parentheses I can just print out

hello

and then I'm just going to add on to this

name

and actually want to put an exclamation point.

so essentially we're getting a name from the user.

restoring it inside of the named variable

and I'm printing it

out onto the screen.

so I'm gonna go ahead and play this ?

and when we run the program you'll notice down here

python is giving us this little problem

so it saying

enter your name.

now

in here I can actually type in of values so I could type in might.

and then I can just hit enter

and pythons going to go ahead and store this value inside of that variable

and then it's going to print out

hello

mike.

and so this is kind of cool and

actually what we could do is we could

prompt the user to enter in more than one piece of information.

so I can actually

copy this line of code.

and I'm an

pasted below here

and why don't we have the user enter in another variable.

so we could have them enter in for example their

age.

and over here we just want to say enter your

age.

so now

we're able to get two pieces of information from the user.

and I could say hello name.

and then I can say

you are

and I'll print out their

age

so I'm going to print

age.

so now I'm basically able to get both of these pieces of information

from the user I can get their name

and I can get their age so when we run this program.

I can type in both of those pieces of information so as they enter your name.

so

we could just

make up a name like john

and then enter the age that say john is twenty five

and now is going to say hello john you are twenty five.

so the program is able to get input from the user and then it's

able to use that information

in order to say hi to the user and

tell them how old they are,

so

getting input from the user is a great way to make your programs more interactive and

here we're just scratching the surface right word just basically getting to know a piece of information from the user but

you can use these inputs to do

awesome things in python and as we go through this course.

you're going to see some

really cool things that we can do

with these inputs

in this tutorial I'm going to show you how to build

a very basic calculator in python.

we're basically going to build a calculator where we'll get to numbers from a user,

and then we'll

add those numbers together and print the answer out onto the screen.

so this will give us some practice in getting input from users and we'll also talk about getting

numbers from users as opposed to just

strings.

so I'm really excited to

get started on this calculator.

the first thing we want to do is

create

two variables and

inside of those variables we want to store

the two numbers that the user wants to add together

so down here,

I'm just going to say,

number one,

and that's what we'll call our first variable

is

equal to.

and now I need to get input from the user so I'm going to say.

input

and inside these parentheses

I'm going to say.

enter a number,

and now I basically want to do the same exact

thing

but for

the second number,

so we'll piece this guy down here,

and I'm just going to say gnome

two

and then we'll just say

enter another number.

so now we're able to store the user's input

inside of these

two

variables.

so now all I want to do is just print out the results so

I'm actually going to create a variable called result somebody's going to say a result

is equal to

and basically we just want to add these two numbers together something as a number one

plus

numb

too.

and now all we have to do is print out the results I'm just going to print

result

so

we basically have our entire program written out here

and this will allow us to enter in two numbers and then we'll add them together and print out the answer

so I could play.

and down here we can enter our number,

so I'm gonna enter the first number we'll say five,

and I'm going to enter my second number so let's say

eight point zero

or else a point

three

it's now should print out the answer,

but

if you look over here.

that's not quite the answer we were looking for at five plus

eight point

three is definitely not fifty eight points three

and here's what happened

when we get input from a user

by default.

python is just going to convert

it into a string,

so it doesn't matter what we put

down their when we're entering the numbers

python's always is going to be like.

ok

this is a string

that's it

sounds good right ?

it's just going to make it a string

in order for us to make these number one and number

two variables numbers,

we're actually going to have to convert the strings that we get from the user

into numbers,

and so

the way that we can do that is by

basically just coming over here

and when we add the two numbers together

I can use a special python function

in order to convert those

strings

into numbers.

and there's actually two

python functions that we could use for this.

the first is called

int

so I could say I auntie.

I can make an

open parentheses and I can make a close parentheses

and basically what this is gonna do is it's going to convert whatever is inside of these

open or close parentheses

into an

integer

number,

and an

integer number is basically a whole number so it's like one two three four or five so it's a,

it's a whole number another word that can't have a decimal point,

so what I could do is I could say

I n t,

and I could put these

inside of

parentheses.

and now what this is gonna do is it's going to convert both of these numbers into

integers in other words

into

whole numbers that don't have decimals,

and it's going to add them together and will print out the result so why don't we do that

we'll just see if this works I'm gonna

click the play button

and down here we'll enter our first number sums can enter into four

and then I'll answer in a five

and now you can see it's printing out the correct answer four plus

five

and so that's essentially our basic calculator.

but we do have one

problem with this calculator salmon run it again and I'll show you guys with that problem is

if I wanted to add in

a decimal number so we'll add four point three and five point five.

you'll see that we're getting this error.

and that's because I'm using this

ain't

function of here and this

int function is looking for a whole number.

so if

I put decimal numbers inside of there it's going to break the programs.

there's another function we can use

instead of an

n we can say float

and a float

is basically just a number that has decimal so it's a decimal number

so I can convert both of these guys into floats

and now I'll be able to use decimal number so I can click play.

and I can just enter into number so I could say like four

and I could also say like five point five.

and now it's going to be able to add

both of those numbers.

even if one of them is a decimal

and that's the beauty of using that little float function so

in certain circumstances you might want the user to only be able to enter into an integer

to a whole number.

but in a lot of cases like in this calculator.

we want them to be able to answer any number that they want so we're going to use this flow

function.

so

I'm just going to recap what we did one more time we created two variables number one and number two

and we basically stored the two numbers that the user's implanted into those variables,

then we converted them into numbers

and

weed

out of them together and we printed out the results so

this is a pretty cool calculator, i'm happy with it.

hopefully you guys learned something.

and as we go forward in this python course you're going to learn all sorts of ways that we can make this calculator more complex

in this tutorial I wanna show you guys how to build a

mad libs game in

python,

so a mad libs game is basically just a game where you can enter in a bunch of random words so like

you know

verbs nouns

names

colors

and

you basically take all of those words and

put them into a story randomly so

over here I had

my web browser I just have

an example of a mad libs so you know

down here were basically just taking random words like an adjective or a noun or a pronoun

and entering them in

sort of a story so like you read through the story than like some random word pops up in

mad libs can be pretty fun and I'm sure

yeah

he's heard of mad libs before,

but if not, now it is a little introduction.

so I want to create a mad libs in python

and this is going to be really cool so

down here I have this, like,

a little poem which says:

roses are red \ violets are blue \ I love you.

and so y'know, this is a compelling classic poem

but

I think we should mix it up a little bit and create a mad lib for this poem.

and so

instead of having this red colour over here,

I want to have the user answer in

their own color

instead of having violets,

why don't we have them answer in

a plural noun.

and instead of saying "I love you"

why don't we have them say "I love --" and then some celebrity

so celebrity.

so

this is the basic structure for our little madlib. right; it wants you basically have the user answering a color

enter in a plural noun.

an answer in a celebrity,

and I'll take

all of those words and

put them inside of our madlib and hopefully we end up with something that's pretty funny.

so

how can we actually go about building this in python well

the first thing we're going to have to do is we're going to have to be able to get these words from the user right that's pretty obvious.

so

I think what we should do as we should create three variables

called color

plural noun in celebrity

and will store

the user's

inputs.

inside of those

variables.

so up here let's create those variables

the first very well I'm going to create is going to be called

color

so it's a color.

and I want to set this

equal to

the

inputs are going to say input

and inside of here I was going to give them a prompts all say answer a

color.

and we can basically just copy this line of code.

and

I'm going to paste it down below

and we'll paste one more time.

so now we're going to create our plural noun

very also I'll say peoria

pluralism now

and want to say answer a

plural

now

and actually over here I want a meager

coal as well.

so then finally we'll create our

celebrity variables they enter a

celebrity and

so now basically we're creating three variables called

color plural noun in celebrity

and inside of them were storing the color that the user enters

the plural noun the user enters and the celebrity these adventures.

so

the last thing we have to do is

replace

these guys with those variables

so

I'm basically just going to add in the colour over here

and we're going to add in the plural noun

so

I can just go like

this.

and finally what is adding that celebrity.

so

now we have a prequel mallet

and it should be functional everything should work it looks like it's

good to go so

let's come over here and we'll run our program

and then down here in the council.

we can play are a little mad libs games so

they enter a color I'm just going to say.

magenta

enter a plural now when we say,

microwaves

and enter a celebrity you at say Tom Hanks.

so

when I click enter what should happen is we should get our mad libs

printed out some

good enter

and now we have our methods was as roses are magenta

microwaves are blue

I love Tom Hanks.

so it's a pretty good madlib

and obviously you know,

the more,

the more print statements we put over here you know

the better the madlib could be and we could store as many, y'know, variables up here as we wanted.

this was just a very simple madlib we only took in

three inputs but you know you could see how you could take something like this and create a little mad libs game so

your homework for this lesson is to go off and make your own madlib game hopefully one that's a little bit funnier than mine.

but that's the basics

of creating a mad libs game in

python

in this tutorial on its artsy guys about working with lists in python.

a lot of times when you're programming in python you're going to be dealing with large amounts of data,

and

when you're dealing with large amounts of data you want to make sure that you can

manage it and organize it properly,

and the list is essentially just a structure that we can use inside of python

to store the lists of information so we can take

a bunch of different data values we can put them inside a list

and it allows us to organize them and keep track of them

a lot

easier.

so generally you would create a python less than you would put a bunch of

related values

inside of that list and then you can use it throughout your program so

I'm actually eyes are just the basics of using lists we're going to look at some of the common use cases and

really just get you up to speed with what lists are and why they're useful so

over here in my program

I'm actually going to

create a list and

we create a list

a lot might we create a python

it's like a normal python variable so

the first thing we want to do and we're making a list

is give it

a name so we want to give it a descriptive name

something that's going to basically describe what's inside the list

in my case for

this example let's make a list

of like friends so we could say here's a list of all my friends so I can say

friends

and I'm going to set this

equal to

the list of values

that represent my friends

and we want to create a list we can use these

opening closed square brackets.

so whenever you use these open and closed

square brackets python basically nose

okay they want to store a bunch of values

inside of this list.

so why don't we go ahead and start adding some values so we can say like my friends are like

tavern,

karen

and say jim.

so here I have three values

inside of my friend's array.

so when we're creating a normal variable in python generally we just give it one value

right

now to create a variable

I would give it

one value may be a string or a number or a boolean.

but when we make lists

were able to store multiple values

inside of the same like

little item inside of the same

object right

and then what I can do is I can access these individual items

inside of my program so

inside of this friends

list were basically storing

all of these different values and that can be really useful so

now that we've stored some values let's talk about what you can put

inside of a list so you can really put any piece of

information in python

we could put things like

strings, numbers, or booleans

so if I wanted instead of just putting strings here I could change like one of these to a number

and I could change one of these to a boolean

and wouldn't matter

python's going to be fine with that.

let's change it back to strings just

for the sake of the example so

now that we've created our list

how can we access

individual elements

inside of this list

it's a good question.

I'm going to go ahead and print something out to the screen.

the first thing we can do is we can just

print out the actual list so

I can just say print friends

and then when I run this program.

if we look down here in the console you can see it's just

printing out the actual list of friends right,

but let's say that I wanted to print

out a specific

element inside of this list

where I can actually refer to elements by their

index

so

each one of the elements inside of this list

has a particular

index

and the index is actually started zero so we would say that this

first element in the list kevin

has an index of zero,

we would say that this

other element

karen has an index of one.

and this

third element jim would have an index of two.

so even though

jim is technically the third element

inside of the list.

it has an index of two

and that's because we start indexing at index position

one.

and so that is kind of how this work and that's how list

indexes work

so

if I wanted to

access a specific element inside of my friends list.

I can just referred to it by its

index.

so over here after which I bought friends I'm just going to tape an

open and closed square bracket,

and inside

this open and close square bracket

I want to put the

index

of the element

inside the list

that I want to access

so fallen to access

this guy right

here this element.

I can just put a zero.

so I can say friends

zero.

and now when I run my program,

it's just going to print out that value it's just going to pronounce

cabin,

if only to access this

gem value over here I can put a

two

and that will give us that

jim value

you can see right there,

so we can access elements

based off of

their index

we can also

access elements

based off of their index

from the back of the list

so

for example if I said

negative one inside of here,

this is going to give me access to this

value right here for jim.

and you can see that's what it does so when we use negatives it starts indexing from the back of the list so if I start at negative two,

this is going to give us

karen

so you can use the negatives to access

items at the back of the list.

just keep in mind though and this is kind of an

interesting

we said we would say this first element here is index position zero

right

but we would say the first element at the back of the list

is index position

negative one so

just keep that in mind.

so there's actually other ways that we can access like just

portions of this list so for example,

let's say I just wanted to select the last two elements in this list and I didn't want us like the first one

will in here I can just say one

with a colon,

and this will grab the element at index position one and

all of the elements

after that so now we should describe

jim and karen

or carrying gym in that order.

I could also specify a range.

so actually let me out in a couple other elements,

just so that we can illustrate this better.

so are in two more names.

so if I wanted to I could select like

the element and exposition one

up to the element at index position three so

it's going to grab

this one says one,

two

and it's actually not going to grab the third one so it's it's going to grab all the elements

up to but not including three so it'll grab

karen and

jim,

let's go ahead and run this and you can see it grabs canon japan so

you can either just put like

one with a colon after it and it'll grab that

in exposition in everything after it or even specify like

arrange that you want to grab from.

so that's how we can access

elements inside of this list

but we can also a modify elements

so for example

I could come down here.

let's say I want to modify this value right here karen

we'll all you have to do is just access that elements I could say

friends

and

karen is that at position of one

and I could change this to whatever I want so I could say friends

in that position one is equal to

mike ?

and now

when we print out friends

and at position one

that value is going to be updated so it's just going to say

mike instead of saying

karen

so it can be really useful to modify values inside of

arrays

so it can be really useful to modify values inside of python lists.

so those are kind of the basics of working with lists

in python and actually in the next tutorial monastery guys

even more ways

that we can use these less we're going to learn how to link

add elements to a less delete elements from a less

copy lists and a bunch of cool stuff

with

these lists but for now this has just been sort of like

the basics of working with lists

in this tutorial I wanna talk to you guys about using

functions with lists

in python,

and python

a list is one of the most important structures where we can store our information.

a list basically allows you to take a bunch of different values and organize them and store them

inside of their own little list

structure

so down here my program you can see I have

two less I have a list of lucky numbers.

and this is just a bunch of different numbers,

and then I have a list of friends

so this could be like a list of somebody's friends

and it's basically just a bunch of strings with names in them.

so these two lists

are storing a bunch of different values and

what makes this awesome is

not only can I store like this many values I mean

I could store

hundreds or thousands or millions of values.

and when you're working with a lot of data and a lot of information and python bees lists are

invaluable.

so because lists are so important there's actually a bunch of different functions that we can use with lists

and those functions allow us to do things like modify the lists

and get information about the list so

in this tutorial

I just want to show you a bunch of those

functions we're going to talk about some of the most common and the most popular functions

that you would use on lists

to make them more powerful and make them more easy to use.

so

the first thing we can do is obviously just print

out a list so down here I'm printing out this

friends list

when a warm

and when I run my program,

you see down here we're just

printing out all the elements in the list so

it's always good to be able to print

out

all the elements inside of a list,

but there's a lot of other functions that we can use so

one function is called the extend function in the extend function will basically allow you to take a list

and

append another list onto the end of it so I could say like

friends

dot

extend

and inside of these parentheses

I can pass in the list

that I wanted to add onto the friends list.

so I could say like

lucky

numbers.

and now when I print out this friends list.

not only is it going to have all the elements in the friends list

it's also going to have all the elements inside the lucky numbers list

you can see down here we have all our friends,

and we also have

the numbers overhears that's a really easy way to essentially just like

add two lists together.

we can also just add

individual elements onto a list

so

I come down here and I could say friends

dot

append

and this will actually allow me to append another item

onto the end of this list,

so over here I could just add another name so we could say

creed for example and now I'm like adding another friend onto the end of this list

so when I run the program.

in addition to having

the original items that were in the list up here.

we also have this additional item at the end

and not a pen function is always going to add the item onto the end of the list,

but let's say that you wanted to add an item into the middle of the list so like right here right here,

there's another list function

called insert

and insert is going to take

two parameters the first parameter is going to be the

index where you want to insert the item so

why don't we insert it here at index position one.

I'm just going to say one

and then I'm going to type in the name of the element that I want to add so

we can just say like

kelly,

and now at index position one we're going to have

the volume kelly

and all of these other values are going to get pushed

up

they're going to

get pushed to the right

one index position so

now I run the program,

you can see we have kavin

this new element

kelly

and then all the other elements have been pushed off to the right,

we can also remove elements

so for example

let's say I wanted to remove this

jim value.

all I have to do is just a friend's dot remove.

and

I can just typing

whatever element I want to remove so

I want to remove

this jim element

is a now when we run the program

jim

is going to be gone from the list and we just have these

four guys left.

you can also remove

all of the elements

from the list so if I just wanted to

completely like

reset the less than get rid of

everything I could just say friends thought clear.

and this is going to

give us an empty list so get rid of

every single element inside the list.

there's also another really cool

nothing which is called

pop

and you can just take out pop like that

and basically what pops is gonna do is it's going to

pop an

item

off of this list so

when I click the play button,

you'll see here that

we're left with

kevin

karen

jim and oscar so

we basically got rid of the last element inside the list and that's what pop does

it pops an element

off of the lists of easily removes the last element in the list.

so we have our list

but let's say that we wanted to figure out

if

a certain element was in this list

right if a certain value is in here so let's say

I wanted to check to see if

my friend

kevin was in this list.

why could say friends

dot

index

and in here

I can just pass

a value so I can say like

kevin.

and this is going to tell me the index

of

caverns are the tell me if

cabins in the list,

so I could play

you can see down here it says

zero

if I was to say like

oscar and here for example

now would give me the index

of

oscar.

so that's it three

but if I put a name that wasn't in here so like

if I put mike

doth not in the list.

and so now we're going to get back

an error

because it's as

mike is not in the list

so that's an easy ways you figure out if a specific element inside of the list.

and if it is,

then you know what index its app,

you can also count the number of similar elements in the list so

I'm actually going to come down here copy this

gem element

and will add another

jim element into here

so I could come down here and I could say friends

dot

count

and

will pass in

jim

and this will tell me how many times the value

jim

shows up

inside of this

list.

so it should say to which it does down there because

we have two

values with

the

text

jim

and so we have all these values we could also sort this list so

I could come over here and I could say

friends.sort()

and what this will do is it'll sort the list

in

ascending order so

we have a bunch of

text here and you'll see what it does.

basically what it's going to do is it's gonna put it in alphabetical order are so

you see we have j k

o and t so

the list went from being just random order like whatever we have up here to now it's in alphabetical order.

and that's also going to work for lucky numbers so I could say late

lucky numbers

dot

sort and then we'll turn out lucky numbers

and they should now be in ascending order,

which I'm realizing they already are up here but if I

was to take this forty two and

put it down here.

now it will figure everything out and put it in ascending order anyway.

we can also reverse

a list

so if I wanted I could reverse this not

lucky numbers list I could say

lucky numbers dot

reverse.

and now when we printed out instead of being forty to eight fifteen sixteen twenty three.

it's going to be twenty three sixteen fifteen eight forty two,

so it's basically just reverse the order of

the list.

and finally there's one more

or

less functional monetary eyes which is copy.

so

I can actually create

another list.

and I could

make it as a copy so I could say like

friends 2.

and we could set this equal to

friends

dot

copy

and now friends

too is going to have all the same

attributes as friends,

because it's basically just like

copy it basically took a copy of that friends list

so

you can see it's the same exact thing and

copying lists can come in handy in a lot of different situation so

those are just some basic list functions and just to kind of like

you know get your feet wet in working with lists

obviously like the more you work with them the more you practice using these different functions the more comfortable you're going to

get.

but that's just kind of like a basic overview of what you can do

in a sartorial

talk to you guys bought tuples in

python.

now a tupel is a type

of

data structure

which basically means it's a container

where we can store

different values.

now if you're familiar with lists

in python

a tupel is actually very similar to a list.

it's basically a structure where we can store

multiple pieces of

information,

but

a tupel has a few key differences from lists

that we're going to talk about

in

this tutorial.

first thing I want to do is I want to show you though how to

create a tupel.

so I can come down here and I can create a tupel

and one of the most

common

examples of tupels his coordinates.

so let's say I had a series of like x y coordinates I could create a variable

called coordinates

and I'm gonna set this

equal to

an

open and close parentheses,

and whenever we want to create a tupel inside of

python we're going to use these

open closed parentheses

and

inside of here inside these proceeds we're gonna put the values that we want to store

so I could for example put a list

of

numbers,

so

this could be like my coordinates I could have like four and five.

so this would be my tuple with coordinates

inside of it.

and one of the things about tuples that makes them unique

is a tuple is

immutable,

and you'll hear that word a lot when we're talking about tuples

immutable it basically means that

the tuple can't be changed or modified.

once we create our tuple up here.

you cannot modify it

cannot change it you can't

add elements to it you can't

erase elements from it you can't

change any of the elements inside the tuple.

what you see is what you get once you create the tuple its

it does it as it can't change

so I can come down here and I can

print out

some of the

attributes inside the tuple.

and the way I can access them

is

just by using an

open and closed square bracket.

and in here I can pass in

a

index

so troubles are indexed

starting at zero so technically we would say that four

is at index position one

and for --

sorry

it is in position zero

and five of them

is at index position one, so if I said

coordinate zero

now it should print out four

and down here we're printing out four.

so if I wanted to print out that five we can just put a one inside of those square brackets

and now we'll print out that five so I can access

the elements

inside of

a tuple I can

easily access is at

each

entry.

but

if I was to come over here and try to change

one of the elements so if I said coordinates

and

coordinate one and I tried to set it equal to something else like

ten

python's actually going to give us an

error when we run this programs often run the program.

you see we get this error it says

type

air

tuple object

does not support

item

assignment

because it's immutable

because we can't change it so

that's basically what tuples are

how we can create them

and

you know a couple like I said it's very simple you just created and then you have,

um.

and now I want to talk to you guys about a common topic in python which is the difference between

tuples

and lists.

so

remember a list is basically doing the same thing

a list.

if one is to create a less we would just use square brackets instead of those parentheses.

and if I was using a list

I could

assign different values to it I could,

I could basically

mutate any of the elements I could add delete

modify change whatever I wanted with the list,

but with a tuple.

we can't do that and that's

sort of the basic difference and

really python

doesn't say anything more than that it basically just says like one of them's immutable one of them's not

but

in practical use cases generally people will use tuples for data that's never going to change

so you'll steal stored dna inside of a tuple

when that data doesn't need to be

mutated that's why something like coordinates

is such a good candidate for a couple because

once you have coordinates like

we're probably not going to modify them right,

we might add

other coordinates.

so for example if I wanted I could create a list of tunnels.

so I can say like

four five

six seven,

maybe we have some other coordinates like

eighty

thirty four.

so here I have in uh

I have a list

and inside of it we have these

tunnels.

but remember these topples can't be modified the values can't be changed so

really it's just a case by case basis

I would say

by a huge majority.

you're going to be using lists most of the time.

topples or more of a niche

you know

they're using more special situations.

but

there are plenty of situations where you want to use tuples so if you're in a situation where you want to store data that can't be changed or mutated

then tuples are the way to go

to some basics about tuples some basics about the difference between

lists and tuples

and so a tuple is a great thing to add in c or

python

repertoire

in this tutorial I wanna talk to you guys are by using

functions in python.

a function is basically just

a collection of code,

which performs a specific task

so I can take

a bunch of lines of code that are basically doing one thing

I could put them inside of a function.

and then when I wanted to

do that task or do that one thing that the function was doing,

I can just call the function

and so functions really help you to organize your code a lot better they allow you to kind of

break up your code into different

you know little chunks that are doing different things and

they're really just awesome so functions are like a very core

concept when we're talking about programming in python,

so i'll show how to create an awesome

function today

let's say for the purposes of this tutorial we want to create a function

that says "hi" to the user so

the one task that our function performs as basically just saying hi to

whoever is writing the program so

over here,

if I want to write a function the first thing I have to use

is a keyword in python it's called "def" of

d e f

and

basically when

python sees this keyword it's going to say

okay

this person wants to use a function.

so after we type out "def"

we need to give this function

a name,

so just like when we

are

creating variables we give them descriptive names.

we also want to do the same thing with functions.

so if I'm creating a function I can just give it a specific name which basically says like what it's doing so

we're going to create a function that says hi so I'm just gonna

call this function,

say hi,

just like that.

and

once we type out the name of the function

and so also I could type out say high with no

underscore or I could type out say high with an underscore.

both are considered like

good practices and python and a lot of times

if you just have a simple like

two word function like this

you don't need to put an underscore but we can put an underscore there

if we wanted.

after we type out the name of the function

I'm just going to type into open and closed parentheses.

and

then I'm going to type

a colon

and basically what this is doing is it saying to python lake

or eye

all the code that comes after this line

is going to be

inside of our function.

and in order to

write code that's going to end up being inside the function we actually have to

indent it sold

over here.

you'll notice that when I clicked enter my

text editor automatically

indented attacks so it's automatically like

using this indent here

and that

having one of the rules and python is like

the code that goes inside of this function

needs to be indented.

so if I was to write some code

like out here,

this is no longer going to be considered inside the function so you can see

as I type out code and obviously this isn't

real code but

as I type text over here that's

invented

this little like marker over here

is basically saying like

oh yeah

that's inside the function.

but then when I write code

over here that is like

not at the same

indentation level as this stuff.

it's no longer considering it inside the function so

that is a little thing any code inside this function needs to be indented

right so our function is just going to say hi to the user so I'm going to have it

print out

some text it's going to say

hello.

user.

so this is a very simple function obviously we just have one line of code and

inside of a function you could have

you know as many lines of code as you want but

for our purposes we only need one line in order to perform our function.

so

now all we have to do is

call this function so

if I want to execute the code inside of this function I have to do something

called

calling it so

if I was to just run my program as it is right now,

I'm just gonna run it,

you'll see that nothing happens over here

right ?

even though this function is

printing out hello user when I run the program

it's not doing it,

and that's because of the code inside of a function

isn't going to get executed

by default.

the code inside of a function is only going to get executed when we specify that we want to execute it.

and in order to do that we're going to have to do something called calling the function so in order to call a function,

you basically just type out the functions name and those open a close parentheses.

so I'm just gonna type out

say hi

and

opening close parentheses.

and

now when we are,

when we run this program again,

you'll see that

it prints out

hello user so were executing the code

inside of the function.

and I want to show you guys just one more thing here

just talking to you guys about how these functions actively work so

up here I'm going to print top

and then down here

I'm going to print

bottom.

so I wanna show you guys the flow of

these functions inside the program so when I

run this program

you'll see

we print out top

hello user

and then bada.

so essentially what's happening is

when python goes through and

executes this

program,

it goes over here to this first line it says

ok

we want to print out the word top

and then it goes down here and it says

ok we want to execute the say high function

so python actually jumps

up

and it goes over this say high function,

and it's going to execute

all of the code

inside of this function so

it's going to go through execute all this code.

and then once it's done executing all the code and the function,

it's going to jump back

down here and it's going to move onto the next line which is bottom so that's how like the flow of functions,

again with functions generally when we're

naming these functions

and

you want them to be named

in all lower case,

and

usually when we're naming stuff in python

if there's two or more words we're going to use an

under space

or an underscore in between them.

so I can write this out as say under score high.

but

in a lot of situations though if I have a function like this where the name is really short

and might just be easier to leave it

without an underscore but

why we've spent on scoring now just to be a

super python official.

all right so now

we can actually make these functions a little bit more powerful and what we can do is we can give them information.

so a lot of times when we write a function we're going to want to have additional information that gets

passed in.

and these are called parameters

so a parameter is a piece of information

that we give to

the function,

so

over here I can actually specify that this function needs to receive some parameters so I can basically say like

hey if you're gonna call this function,

you need to give us some information,

you need to give us some parameters

and all I have to do to do that has just type out the name of the parameter that I want to receive so why don't we allow the

code calling this function to tell it what name to say hi to

up here I can just say name

and basically what this means is it means whenever I call this say high function

we have to give it a name.

so down here if I was to call this

I have to include a name in here so I can say like

mike.

and what we can do now is we can actually access this parameter or this variable

inside of our

function so I could come over here and instead of saying hello user.

I could say hello

name

and basically what this is gonna do is it's just going to say hello to whatever name got passed in here

so I'm actually gonna copy this

and

we will

do this twice also hello my kilo

steve

and now when I run this program

you'll see that

instead of just saying

hello user

it saying hello to whichever name

I passed in to the function.

so that's why this can be really useful right we can

give the function information

and depending on the information we give it

it'll performance task

a little bit differently.

I could also

include more than one parameter so you can I mean

technically you could have as many parameters as you want

so I can put another one in here would say

age.

and now I'm going to have to pass in an

age

along with these,

so I'm just going to pass in

age

and

passing an age for down here,

and I'm just going to pass in

strings,

so we can say hello name

you are

age

so I'm passing in two pieces of information.

now when we run this program is going to call the function,

and it's going to use both of those pieces of information so it's a healthy

like you are thirty five hello steve you are seventy.

so

essentially you

were writing out this one line of code which just prints out like hello to someone

and were allowing this function to receive

two parameter so the name in the age

and depending on the name in the age,

the function is going to print out

hello a little bit

differently.

that's kind of the beauty of using function so

you could pass anything you want into a function so for example,

I could pass in a

integer.

instead of a string for the age.

so like I could pass in a number.

the only differences over here we're going to have to

convert this into a string,

but it's going to work.

just the same,

so you can pass in alm

strings

numbers bullion's

arrays you can really pass

any type of data

into a

function and it's going to work

so

you can see here we get the same result.

so that's the basics of functions and as you go through on

with python you're gonna you know

being functions more and more,

and generally it's a good idea to break your code up into different functions so whenever you have like a grouping of code

that's

designed to perform a specific task.

that's usually a good candidate to be put inside of a function

in this tutorial I wanna talk to you guys about using the return statement in python,

functions

and other python function is basically just

a collection

of python code that performs a specific task.

and when we want to perform that task in our python programs we can call

a python function

and a lot of times when we're calling a python function we just gonna call it and it does its thing and then we move on with the program.

but sometimes when we call a function we're actually going to want to get

information

back

from that function.

so when I call the function I want to basically

executes task I wanted to execute all the code

and then I wanted to like

give me some information back

so that can be like a particular value.

it could be something like telling me how the task went

basically

the

function can just communicate back to us like hey,

here's some information.

and that's what the return keyword can allow us to do

the return keyword can basically allow

python two return information from

a function.

so I'm gonna show you guys how we can

do this I want to create a very simple function.

and it's just going to

cube a number so when we cuba number we take it to the power of three so if I was going to cuba like to

be like

two raised to the power of three

right it's just

pretty basic math.

so we're gonna make a function that will cuban number

and I'll show you guys how we can use that return statement

so

first thing we want to do is make a function.

I'm just going to say

death

q,

we'll call the country

the function cube.

and

over here we can specify any parameters that this function will take.

so basically any values that we want to give this function so we're going to give it one function which is just going to be

a number so I'm just going to call it numb.

and then over here I'm going to

type out a

colon

and then down here,

we can put any of the code

that we want to be included in this function.

so basically this function is just going to keep this number so we could just

take out numb

times numb

times numb

right

that's going to give us

numb cubed.

so

that's all well and good.

and if I come down here I can

execute this function so I can basically just call it as a cube.

and why don't we pass it a three.

so I'm going to go ahead and pass it to three

and I'm going to save this.

and

now let's go ahead and run

this code,

so we're on the code

and

you'll see down here.

nothing happened

right so nothing got printed out

in our program

facts

when we call this cube function

it didn't really do anything,

so

let me try to print this out so immediately prentice

function out it'll give us back the information that we want so

what about print

and will print

out the value of the function I'm terrific play

we look down here it says none.

so when I printed out

the value of this function it told me none

but really this function is supposed to be q being the number.

and

here's how we can use the return statement and python

I can come over here and I can just say

return

and now

python is going to return whatever value we put over here to the right.

so when I call this cube function and I give it a three

python's going to go off it's going to execute this function

when it sees this return statement

it's going to say

okay,

I want to give a value back to whatever call of this function.

and it's going to return

this value.

now when I print out

cube

three

it should print out the answer because we get an answer back so

when I play this

you'll see

down here,

says

twenty seven so we got the correct answer.

so I can do this with anything wantonly cube like for something

as an hour on this

and you can see we're constantly getting the correct answer back

so

that's the basics of using this return statement it allows us to return a value back to

the caller in other words

back to whatever's calling the function.

so I just wanna illustrate this point a little bit further I'm going to go up here I'm actually going to create a variable

so I'm gonna create a variable called result

and I'm just going to set it

equal to

cube

for

this variable result is going to store

the value

that gets returned

from the cube function since

it's not in a store like

cube for its going to store the value that gets returned from executing that function.

so now if I came down here and printed out result.

it's actually just going to turn out sixty four again because

that's the value that it's storing

so this return statement can be really useful for like

getting information back from a function,

we can use

something like a parameter.

I guess for as a parameter.

we can give information to a function

and then we can use the return statement to get information

back from a function.

and I do I just want to point out one more thing

I'm actually not able to put any code.

after this return statements so if I came down here and try to put like a prince statement.

this actually isn't going to work so

this is never going to get printed out so if I just typed out like

code right here

when we run this program.

it's not going to type out

code

does because when I used this return keyword,

it breaks us out of the function so

python's going to go through it's going to execute the code

in the function whenever it sees this return keyword.

it's just going to break back out and we're going to be done so we'll never be able to reach

this line of code.

so that's the basics of using return statements and you can return

any data type you want

we could easily return like a string or boolean or an array.

it doesn't really matter you can return whatever you want.

and a lot of times in a lot of situations you're going to want to get a value back from

a function

in this tutorial I wanna talk to you guys about using

if statements in python.

now

if statements are a special structure in python

where we can actually help our programs to

make

decisions.

so by using an if statement

I could execute certain code when

certain conditions are true,

and I could execute

other code when

other conditions are true.

so basically if statements allow our programs to respond

to the

input that they are given so

depending on the data that we're using in the program

are programs will be able to respond so when certain data is certain values we can do certain things

and when other data is,

other values

you can do other things so

you know

your programs are essentially

becoming a lot smarter

and actually if statements

are things that we as human beings deal with every day so

you know as you go throughout your day generally you're dealing with if statements all the time so I want to kind of

give you guys a brief introduction into if statements and we'll talk about some of the common if statements that you'd see in everyday life.

and now we'll go ahead and do a really awesome example of the kind of like

sure yeah

what if statements can do for us.

so

over here in my text editor I just have this little text file

and in here I wrote out a bunch of

if statements

that

a lot of people will encounter on a daily basis so here's the first one it says I wake up

if I'm hungry.

I eat breakfast.

so let's break this down a little bit up here it says

if I'm hungry.

and this is a condition.

right

this is either going to be true

or it's going to be false,

right

if it's true,

I'm going to go ahead and

eat breakfast right

if it's false

under skin to skip whatever was in here and move on,

writes that

the basics of an if statement.

we have a condition

in this case

if I'm hungry.

if the condition is true,

then we do the action so

we eat breakfast.

otherwise we just skip it.

so down here we have another one.

it says

I leave my house.

if it's cloudy.

I bring an umbrella.

otherwise

I bring

sunglasses.

and so this one is a little bit more complex than the one we just looked at you'll see we have our condition right says

if it's cloudy.

if that conditions true

we're going to bring the umbrella.

but

in this case if the conditions false

there is something else that we want to do

so in the case of here if this condition was false we just moved on.

but now if this conditions false

then we're gonna go ahead and bring

sunglasses

so

that's another example of an if statement it's a little bit more complex.

finally I have one more down here and this one's even more complex it says I'm at a restaurant.

if I want me.

I order a steak.

so if this conditions true

we order the steak,

but if this condition is false,

then we're going to move on and we're actually going to check

another condition.

so I'm gonna say

otherwise

if I want pasta.

I order spaghetti and meatballs.

this is another condition.

if this condition is true we get the spaghetti,

if it's not true

then finally we're going to move on down here

and which is default to ordering the salad so

all three of these if statements are

valid if statements

it's just

they get more and more complex as we go down the list

so

hopefully that's

you know

kind of wrap your head around what if statements are we're basically specifying conditions.

if those conditions are true we're going to do certain things

and those conditions are false we can do

other things.

or

we can check

other conditions

aren't so let's head over to our python file and we'll start writing some actual python.

so in here in my app dot python file.

I want to create an

if statement

and I'm going to show you guys a very basic if statement in this tutorial.

and then in the next victoria we're going to look at some more advanced

if statements.

so what I want to do is create

a bully invariable.

so I'm gonna create a boolean variable that's going to store whether or not the user is a male.

so it's just going to be called

is underscored mail

and I'm gonna set this equal to true

because I'm a male.

so we have this boolean variable right and right now we haven't set equal to true.

I can actually use an

if statement to check to see what the value of this variable is and if it's true I can do something so

if I want to use an if statement all I have to do is just type up

if.

and then

I just need to type out

a condition.

so

basically I would have to type out like

something that's going to be true or false

like

for example in

the other page we are specifying like

if I'm hungry or if it's cloudy.

here we're just going to check to see

if

is male.

so in other words

if the person is male.

so remember this has to be a

lake

it has to be able to be reducible to a true or false value.

so in our case

where it is using a boolean because that's like

the easiest thing we can do.

so

I said

if

I specify my

true or false condition.

now I'm just type a colon.

and

what I want to do now is make a new line.

and so

anything that I put below this with an indentation

is actually going to be

executed when that conditions true so I could put

print

and down here I can just put

you are a male.

and now you'll see what happens when I run this program.

it's going to go down here and it's going to say you are a male.

but if I changed his mail to false

so instead of this being true I'd just change it to false.

now all of a sudden it's not going to

print anything.

so it's just going to be blank down here.

that's because this condition wasn't

true.

so anything that I put below this

if declaration and

that has an indentation like that

is going to be executed when the if statement

is true.

we can also use another keyword in

python which is called

else

and alice is basically going to be like

otherwise so you remember,

before we said

if it's cloudy.

I'll bring an umbrella,

otherwise

I'll bring sunglasses well this is going to be like our otherwise

so I can say down here.

else

and now

anything that I've put below else

is going to get printed out when

that condition

isn't sure

so long we just put

you are not a male.

so now

we're able to cover both of these situations for this variable.

if it's false we can cover that situation.

so it says

you are not a male.

if it's true

we can cover that situation as well so it'll say

you are a male,

so that's pretty cool.

but we can also make these more complex

and actually before I talk about that you can put as much code as you want inside an if statement so I could have like

dozens of lines of code if I wanted.

I'm just giving you guys are very simple example

so

why don't we make this more complex and I'm gonna add another

variable into the mix

so I'm going to add another you know boolean attribute into this mix.

I'm going to make another variable called

is tall

and we're gonna set this equal to true as well.

so

now I have

two variables in the mix.

let's say I wanted to write an if statement that will check both of those variables.

so I could write an if statement that's like

if their mail and their tall or

if they're male and they're not taller

if they're not mail in their tall like

I can write out a bunch of

if statements

to check

the combination of these variables

and so the way I can do that is by using one of

two key words

so

the first keyword I want to show you guys is the

or keyword.

so I can come over here and I could say

if

is male

or

is

underscore

tall.

and what this is basically going to do is it's going to say if the person is either male

or

if their tall,

then we want to do something so

this is only going to be true when one of these values

is true

when one or both of those values is true

so down here we can actually put instead of you are a male we could put you are a male

or tall or

both

that's going to be

more appropriate.

and then down here we would say you are

neither male

nor

tall

and that's because

if we execute the code inside of this else

that means that

both of these guys are false

rates I'm saying

if they're male or their tall,

we're going to execute whatever isn't here

otherwise

that means

they're neither male

nor tall we're just going to execute this down here so

misery as how this works all

click play.

and these are both true so it's going to say you are a male or tall or both.

if I was to set one of these to false

so let's set his male eagle

false.

now,

it's still going to say you are a male or tall or both.

but if I set them both equal to false.

now it's going to

say you're neither male

nor tall.

so

that's how the basics

of using the or operator.

and there's another operator we can use which is called

and

and basically a

similar to

or accept

both of these

conditions have to be true so

this is basically saying

if the person is male,

and

they're also tall,

then we're going to execute whatever's in here so we could actually change this text

to say

you are

a

tall now

because we know for a fact that

if this is getting executed that are both male and tall.

we can also change

this print statement down here,

this could say you are

either

not mail or not tall,

or both.

so

you can see it's basically just saying that

you're either

not one of them or you're not both of them so

we could the play button

and you'll see because they're both false

it's going to say you are either not mail or not tall or both.

but if I make them both

true,

now it's going to say

you are a tall male.

if I was going to make one of these faster so let's make

is tall false.

now it's not going to execute this first print statement it's going to execute the one inside of the else,

so to say you are either

not mail are not tolerable.

so

that's the basics of

and and or

and you know

you'll be using those a lot of them as you use your if statements,

but there's actually one more

thing we can do we can add in some more conditions

so up here I'm checking

if their mail and their tall,

but what if I wanted to check if their mail and they're not tall

so they're like a short male

I can use another

keyword in python

called

else f

or really it's just typed out

yes

I am,

and it stands for lcds.

and after this we can put another condition so

over here I'm going to check to see if their

male and they're not tall,

so I'm gonna say else if

mayor

ismail,

and

now I can type in

not tall.

and the way I can do that is by saying

not

an

open and close parentheses

and saying

is tall

and basically when I use this not function,

it's going to negate

whatever is inside of here so if this was true,

it's going to make it false and if this was false it's going to make it true.

so basically that'll tell us whether or not their tall

and that I'm going to use a colon and now

down here

inside of here were basically just going to type out any of the code that we want to happen

when this condition is true

so down here we can just print out

you are a short

male,

and

there's actually one more condition that we want to check for which would be if they're not mail and their tall,

so we can make one more

lcs.

and I'm actually just gonna copy this guy

and we'll paste it down here.

so I want to say,

if

not,

is male

and

his tall,

so now we're checking to see if their mail

and

are either not now and their tall so here we could say

you are

a

you are

not a

male

but are tall.

so

essentially here we have an

if statement that's going to cover

every single condition

for these two variables so

in every single situation of the two values of these variables

were going to be able to print something out for it so

if I mean both of these true

it's basically going to tell us.

you are a tall male

if I make

is male false

it's going to tell us.

you are not a male butter tall

if I made is mailed true

and is tall false,

then

it's going to tell us you are a short male

and if I made both of these false

it's going to tell us

you are either not

male or not taller both and actually we need to change this so this should say

you are not a male

and not tall so that would be a better print out

for that situation so

you basically see how we can use

ifs

osoph's

and

else in order to

how I programmed to make decisions

and really to respond

to the different data in our programs.

so unable to respond to every combination

of the values for these two

variables and that's really cool so

in this example we were just using simple boolean variables

but in the next tutorial,

I'll show you guys how you can actually use something called comparison operators.

so we could compare like two numbers or two strings

and we could use those as are conditions

but

for now I think this is a good introduction into if statements.

so I'll see you guys in the next tutorial,

in this tutorial on a talk to you some more about

if statements

in python.

more specifically we're going to be looking at using comparisons

inside of our if statement so

if you're following along with the course

in the last tutorial,

I talked to you guys about

just the basics of if statements and we used a couple different boolean variables

and depending on the diaries of those bullion's we're able to do certain things

in this tutorial we're going to look at another way to use if statements which is with comparison so,

instead of just using boolean values we can actually compare

different value silly I could compare a couple of numbers like

compare couple strings

and depending on the results of those comparisons we can do

certain things so

this is going to be pretty cool and this is really going to give you guys a full understanding of what you can do with if statements so

for this tutorial I actually want to create

a python

function

and this function is going to

give us the maximum number that we pass into it so

this function is going to take three parameters as input,

and it's going to print

out

the

biggest

number that we give it so

let's create this function I was going to say,

death.

and I'm just going to call it max

numb

and

inside of these parentheses I'm going to specify that I want three parameters as input.

someone to say

number one,

number two and number three.

so basically

we're passing it three numbers and

this function will

return.

the largest

of the three.

so in order to figure out which of these numbers is that the largest

we're going to have to use an

if statement.

so I can say

if.

and

over here I need to specify

a condition.

so I need to put like a true or false

value.

and so what we can actually do is we can compare these different numbers so I could say if

num one

is greater than or equal to

number

two,

and

number one

is greater than or equal to

numb three.

so basically what I'm doing here

is I'm comparing these different number so I'm saying if

the first number is greater than or equal to the second number

and

this is a comparison so

when you think about it

when we compare these two numbers we're going to end up with a true or false value

write

num one is either greater than or equal to numb to or it's not

it's actually a boolean

value

rights either true

or it's false.

same thing over here.

the result of this comparison

is either true

or it's false

so technically I'm putting a true or false value in there.

I'm just getting that true or false value by using a comparison.

and you'll notice over here we're using something called a comparison

operator.

and basically this is just like

how we want to compare them so

we're saying like greater than or equal to in this case

so down here.

if

this whole condition is true

in other words of the results of these two comparisons end up being true,

then we know that none one is the biggest

so I can just return

num one

I can say return

no

one

but we also want to check some other condition so I can say

alef

and

now I want to do some other comparison so I'm going to say,

else if

none

too

is greater than or equal to

number one

and

number

two

is greater than or equal to

number

three.

so I'm doing essentially what I did up here except for none too so again I'm comparing

these different numbers and this is gonna end up being a true or false value,

depending on the result of the comparison

so

down here again

we can just

returned home to

because if all this is true that means we're going to end up returning

none too.

and then finally we can just say else

so

if

num one isn't the biggest and numb to isn't the biggest then

we can pretty much assume that

number three is the biggest so

now we have

our function

so

down here

I'm actually just going to call this function,

so I'm just going to say,

actually I'll print out the results I'll say max

numb

and will pass in like three four or five

so

we're basically calling that new function that we just made.

and

I'm going to go ahead and run this program.

so you can see down here

in the output

we printed out five because that was the biggest.

if I was to change this middle onto the biggest so we make the middle on forty

now it will be able to

take on that situation and finally I can make this like three hundred

and

it'll be able to handle that so

no matter which number numb one number two or number three ends up being the biggest

it's

able to

tell us without a problem.

so

these comparisons are a really really really common way to make if statements and a lot of times

you're gonna want to be comparing different values

inside of python,

so over here we're comparing

numbers.

but we could also compare strings

so I can

easily make these both like

you know I can

make this like dog

and I can make this dog

and I could say

a different operator so I could say like

this double equal sign would mean equal so I can basically say like

if this string is equal to that string.

you can basically like compare

all different data types see nike compare in numbers strings.

you can also compare

bullion's

so

once again

these are

comparison

operators and

this one is greater than or equal to but there's a bunch of other comparison operators we can use so

the most basic is just going to be a double equal sign

and not basically checks to see if the two values are

equal

so it'll say like,

if

number one is equal to

number two,

we can also say not equals

and this exclamation point will basically mean

not equal so it's.

if no one is not equal to

none too.

we also have greater than,

less than,

greater than or equal to

less than or equal to.

and those are kind of all of the operators

are all the you know the basic

comparison operators that are going to be using in python so

using comparisons is really awesome and there's going to be tons and tons of situations

inside a python where you're going to want to compare different values

so

these can be extremely useful

in this

tutorial on how to talk to you guys about building a calculator in python.

now having been fallen along with this course you'll know that in the beginning of the course we actually created a very basic calculator.

basically the user could just enter into numbers and our calculator would add the numbers together and spit out the answer

in this is horrible honorary guys how to build a more advanced calculator so

this calculator is going to be able to perform all of the basic arithmetic

operations so we can add subtract multiply and divide

and were actually allow the user to specify which one of those they want to do,

so the user will enter in a number.

they'll enter in whatever operator they want to use so plus minus

divide

mocked by,

and then I'll enter in the second number and will perform the operation

for them says it can be pretty cool.

and it's going to show you how we can use

if statements

in like a

practical application

so let's get started.

the first thing we want to do

is get

input from the user so I'm going to create

three variables one for the first number one for the second number and

one for the operator

and will basically store the values that the user inputs

into those variables so the first one will just be number one

and I'm gonna set this equal to

input

and we're going to give this a prompts also

enter

first

number

and here's actually the thing is whatever the user

enters.

we're going to want to

convert it into a number

so

generally in python when we get input from the user no matter what they put in it just gets converted into a string.

but we don't want a string because we're going to have to

be adding or subtracting and multiplying these numbers together ?

so whenever they enter in

the number I just want to immediately convert it

to

an actual like number data type instead of a string.

so what I can do is I can actually say float.

and I can surround

this entire input tag

with parentheses.

and now,

what this is gonna do is it's going to immediately convert

whatever the user inputs

into a float.

now that's going to mean that they're going to have to insert a number otherwise we'll get an error

but

for the most part this should work out for us so I'm actually just going to

copy their sky

and we'll go ahead and

paste it over here,

and we'll paste it one more time so we

were basically just try to get three pieces of input from

the user.

so the second thing we want to get is the operator so I'm just gonna say

oh p

for operator and actually get rid of this flow

because

we want to keep this as a string.

and I'll just say

enter

operator so it's going to be like.

plus minus

multiplication whatever.

and then finally down here we'll get numb

to

and again we're going to want to convert this to a float,

so I'll say

enter second number

so

now basically what we're doing is we're getting the first number we're getting the

operator and we're getting the second number from the user.

so

what we need to do now is we need to figure out

what is inside of this

o p.

in other words we need to figure out what

operator.

the user was

trying to do so are they trying to do additional they're trying to do a subtraction like

we want to figure that out,

so

we can use an

if statement

in order to

figure that out so I'm gonna come down here

and

I'm basically just going to create an if statement song and say

if.

and

we want to check a condition so I'm basically going to check to see if this operator is equal to

a plus sign

so I can say if

o p

equals

plus sign

and now if the operator is equal to a plus sign.

I'm just going to print

out

number one

plus

none too.

but let's say that instead of a plus sign they entered in something else so we can say

l f

o p

is equal to.

and now we'll check if it's a minus sign.

and so here or just print

num one

minus

nothing too.

and I actually forgot to put a colon here.

so we can just do these for everything so now we can say.

lf

opie

is equal to

division

and here we'll just divide the two numbers so I can print out

number one divided by numb to it,

and finally we'll do the same thing for multiplication so I'll say

l

if

opie

is

equal to

astronauts

and was print

out

number one times

none too.

so basically over here we have every

you know condition.

but I also want to put in an

else

statement so

in the case that the user enters in an operation.

that's

not

like one of the four that we specified up here I just want to throw an error sums usa

opie

are actually we just say

else

and here with this print out lake

invalid

operator.

so

this if statement should give us everything we want basically I'm just checking to see

if it's

equal to a plus sign a minus sign the division sign or a multiplication sign !

depending on which one is equal to we'll do a different operation so

let's go ahead and run this and see how we do so

I'm going to run this program

and it says enter first number let's enter five

enter an operator so why don't we just

do addition

and enter a second numbers do twenty three.

so now

it prints out the answer twenty eight so

our calculator actually works

let's try another

operator just to make sure.

so it would be six

and y we multiply it

by I don't know five point

to three.

so now we go off and we do the multiplication and looks like we got our answer so

our calculator seems to be working and so

basically all we did was we got the input from the user.

and then we used

if statements to figure out

what they wanted to do right so we could check to see if they want an edition we could check to see

if they wanted subtraction

division and multiplication.

and we can also check to see if they entered in an invalid

operator so actually why don't we try that too.

so enter it in like five

and now what does enter unlike

an open or close parentheses and

four,

so you can see here it's

able to

tell like the program smart enough to know that

that's not a valid operator so

these if statements can be really powerful and we can use them in combination with getting the user inputs to create a little calculator.

in this tutorial on hitachi guys by using dictionaries in python.

now a dictionary is a special structure in python which allows us to store information

in what are called

key

value pairs.

so essentially I can just create a bunch of these different

key value pairs.

and then

what I want to access a specific

piece of information inside of the dictionary.

I can just refer to it by its

key,

so the word dictionary is actually pretty appropriate here if you are familiar with a normal dictionary,

you know in a normal dictionary you'd have a word,

and then

you'd have a definition associated to that word so

in this situation the word would be the

key.

in other words the word is what like uniquely identifies it

inside of the dictionary,

and then

the value would be the actual definition so

this is going to make more sense once we start working with this but

I just wanted to give you guys a quick introduction.

so in this situation

I want to create a little program

that will allow us to convert

a three digit month name

into the full month name

so I can convert

for example like

jay

a n

two

january

or I could convert

an

a r

into

march.

like I want to be able to have a program that can do that for us and that's actually a pretty good use case for a dictionary so

we're actually going to create a dictionary.

and I'm sure you guys how we can do that so,

the first thing we need to do

in creating a dictionary is just given a name,

so I want to give this a specific name so I'm just going to call this

month

conversions.

and now I just want to set this

equal to an

open and closed curly bracket

so whenever we create a dictionary in python.

we're always going to wanna

created inside of these open and closed

curly brackets

so

inside of the dictionary now we can start defining what are called key

value pairs.

so I can define a key and that I can give it

a

corresponding value.

and the way that we can do that is by typing out the key and then typing out the value so

in our case we're converting three digit month names

into the full month names

so I would want to type out for example

j n

and

then I can type a colon.

and

I want to type out

the value I want to associate with it so we can say in january.

I could basically do this for every combination so I could say like

you'd be

and this would be

february

and actually after each one of these we're going to need to put a comma.

so I could do the same for march soon say and they are.

so essentially what I can do is I can specify an entry

inside of this dictionary for

each one of these so

this over here would be the key

in this over here would be the value.

and here's one thing is all of these keys have to be unique.

so if I was to come down here and change this to j n,

this is actually going to give us a little warnings you can see down here it says

dictionary contains

duplicate

keys

dots they know no one we're creating dictionary so

you'll want to make sure that

the keys are unique

aren't so I'm gonna go ahead and

create one of these for each one of the months

and then we'll come back and we'll talk about it.

all right so I've gone ahead and created an entry for all twelve of the months so now

we have a bunch of unique

keys

and each one of those keys is associated with

a different value.

so this is the basics of creating a dictionary is we have a bunch of these different key value pairs.

and now what we can actually do is we can

access them from

inside of this dictionary ?

so if I wanted to access

a specific

key or a specific value.

all I have to do is come over here and I'm actually just going to

print it out onto the screen so we can see it.

all you have to do is referred to the dictionary by name so it's just called

month conversions.

and

there's actually a bunch of different ways

that I can access these month names,

so

I could access

different entries inside of this

dictionary ?

the first way is just by making

a

open close square bracket

inside here I can just type in one of the keys.

so for example inside here I could type in

and

oh thee.

and what this should do is it should give us back.

the

full

name for november so when I print this out,

you'll see that we get back down here.

nov.

so I can do the same thing for

any of these we can say like an a r.

and now we should get marched back so

I'm able to refer to the key,

and it's going to go into the dictionary and it's

going to give me the value that's associated to that qe

is actually another way we could do this too so I could

say

month conversions dot

get

an inside of here I could also pass in the name of the key so I could pass in like

d c

and now we'll be printing out

december.

and what's cool about using this get function

is I can actually specify a default value that I want to use.

if this keys not found so

there's going to be certain cases when we're dealing with dictionaries where you're going to put in a key

that might not necessarily

map to a value

inside of the dictionary you so he put in an invalid

key.

so let's just

try to do that so honest put like aliyu v.

that's not

a month abbreviation.

so when I try to run this,

you'll see we get this

none

down here.

and in a lot of cases

you're gonna want to

create some sort of a default

value.

so if I'm in this situation where I have a key

that's not mappable to any values inside of this

dictionary ?

I can actually pass it a default value.

so inside this dot get function

I can

make a comma.

and I can pass in like a default value to get printed out so I can say like not

a valid

key.

and now

when I put in the invalid key instead of saying none.

it's going to go ahead and say

not a valid

key and so this is going to give us like a default value

that we can fall back on so

these dictionaries are really awesome and

the keys over here don't have to be

strings so you could also use numbers

so for example I can see like zero

one

tan like I can put any numbers I want over here as keys

as long as their unique and that I could access those keys

just like I normally would down here

with this

get function or with those open and closed square brackets

so that's sort of the basics

of using dictionaries like me really useful to store

key value pairs

and honestly you're going to be using them a lot in python to store different types of data.

in this tutorial I wanna talk to you guys about wild loops in python,

and

a while loop is basically a structure in python which allows us to loop through

and execute

a block of code multiple times.

so I could specify like a few different lines of code and then I could

put that code

inside of a while loop

and it would basically you loop through that code executing it repeatedly until a certain condition was false.

so our lives can be awesome and there's a lot of situations in python where we're going to want to loop through specific lines of code,

so in this tutorial I just want to show you guys the healing

bare basics of how wildebeests work

and then in future tutorial is we're going to use while leaps to create little games and stuff like that so

let's talk about wild sum

when I create my wild loop.

the first thing I want to do actually

is create an

integer.

I'm basically creating a variable that's a number and you don't have to do this for a while

but just for our demonstration I'm going to.

so I'm going to call this,

I

am going to set it equal to one.

now what I wanna do is I want to create a while loop

so I'm basically just going to say.

while

and

over here I want to specify

a

condition,

and this is what's called our loop condition or you can also

refer to it as a loop

guard

and basically we are going to keep looping through the code

inside of the while loop.

as long as this condition is true.

so whatever condition I put in here as long as it's true

we're going to keep looping through the code inside the wild is I'm just going to say while

I

is less than

or

equal to

ten

and now I'm gonna put a

colon

and I'm gonna make a new line.

and so

anything that's below this while loop declaration and that's

indented

like this

is going to be considered code that's

inside the while loop and so that code

is going to get repeatedly executed

while this condition up here is true.

so I'm just gonna put a very simple line of code here where it's going to print

out the value of

I,

and then down here I'm going to actually

increment

eyes I'm going to add one

to eyes I must say

I

is

equal to

I

plus

one,

so basically I'm taking this I value and I'm adding one to it

is actually a shorthand that we can use in

python to do something like this though I could just say

I

plus

equals one

and not automatically going to add one

to

I

so this is like a little shorthand and

you'll see people in pipe on using that a lot.

so

over here we basically have

our wild lives I have

the outline for a while lives we're defining this variable up here

and we're going to keep looping through the code

inside the while loop.

as long as this condition up here

is true.

so if this condition is false for example if

I

is equal to

eleven,

then we're not going to loop through this company more than just going to move on.

so down here I'm actually just going to print

done with loop.

so this was kind of illustrate this for us.

so let's go ahead and run this program I'm just gonna run it

and

you'll see down here we get some

output so

we're actually going to get

numbers printed out one

all the way down

through

ten

and then were printing out done with loop

so basically what's happening is we're printing out

every time we go through this loop

so

initially I is equal to one right.

the first thing that python's going to do when it gets to this while loop

is it's going to check this condition.

so before it does anything else,

it's going to check this condition and it's going to say

okay,

is

one

less than or equal to ten.

and that's true.

so as long as this guy is

true

we're going to go through and loop through all the code inside of here.

so we're going to print out

I

which has the value of one

and then we're going to

add one

to I so now I'm going to go from one

to two.

now what we're going to do

is we're going to go all the way back up here

to this while loop

declaration and we're gonna check the condition

again.

so remember I checked the condition

first time

and then I looped through all the code,

then I'd go back up to the top

and I check it again so I'm gonna say

ok

is I less than or equal to ten

at this point

I is equal to two

so I is less than or equal to tenant.

so now we're going to go through and will

execute all this code again so I'm going to

print out

I so it's going to be too

and I'm going to add one to eye

so now we have three

then

python's going to go all the way back up to the top

and it's going to check

the condition again

so

on every iteration through the loop

before python

does what's inside of this loop

it's going to check that condition.

and as long as the condition remains true.

we're going to

keep executing the code inside the loop

eventually though in this program

I is going to end up being eleven

right

so I'm the last

iteration it's going to end up being levin,

we're going to come back up here,

and we're going to say

hum

is eleven less than or equal to ten

nope

and so sense it's nope

we're going to come down here

and we'll print out this done with loop line so that's the basics of how these wildebeests work

we're specifying a loop condition.

as long as that conditions true

will keep executing the code

inside of the loop,

and after every execution of the loop,

we're going to come back up and check the condition again so

that's how we end up with

this.

printing out

down here,

so that's the basics

of

a while loop

and

we can use these volumes to do

all sorts of things like wild fruits are very very powerful

in this tutorial on a show he eyes how to build a basic

guessing game in python,

and in this guessing game we're actually going to be using all sorts of cool programming structures that we've

learned up to this point in the course.

so we're going to be using things like

if statements and wild loops and variables and

all these cool things

in order to build this game so,

the basic idea is we will specify lake a secret word.

so we'll have a secret word that we store inside of our program

and then the user can interact with the program and try to guess

the secret word.

and so what we want to be able to happen is we want the user to be able to keep guessing

what the secret where it is and keep typing in different responses.

until they get the secret word right.

so that's the basics

of what this game is going to be.

and

now let's go ahead and create it so the first thing we want to do is

create a variable to store our secret word.

so I can say

secret

word.

and we're just going to set this equal to a secret word so why don't we make it a draft.

that's a pretty good secret word.

and now what we wanna do is want to create a variable that will store

the user's response

so I want a variable that will store like all the guesses

that the user makes

so I'm just gonna

call this

guess

and

I'm just going to set it

equal to an empty string right now.

so

now we have a secret word

and we have

a variable to store the user's guess

and what we need to do is we need to be able to prompt

the user

to input the secret were.

but here's the catch.

what we want to happen is we want them to enter the secret word.

and if they don't guess it correctly

we want to prompt them to enter it again.

so we can't just use a single

input statement we actually have to use

something called a while loop.

and we can use a while loop

in order to continually ask the person

to guess the word

until they guess it correctly.

so let's go ahead and create our while loop so I'm gonna say while

and

after a while I need to specify a looping condition or a looping guard.

basically this is something

that as long as it's true

we're going to keep looping through

this loop.

so basically I want to say

I want to keep looping as long as

the user's gas

is not equal to

the secret word.

so as long as they haven't guessed

the secret word.

I'm going to keep going through this loop,

and inside this loop.

what we're going to do is we're going to ask them to input the secret word

so I can take this

gas variable

and I can set it

equal to

input.

and I'm just going to say.

enter

guess.

and so over here we're basically telling the user to enter in their guests.

I'm storing whenever they enter

inside of this guess

variable

and then what's going to happen is that we're going to come back up here

we're going to

check to see if the gas

is equal to the secret word

if the guests

isn't equal to the secret word,

then we're going to do it again.

but if the guests

is equal to the secret word,

then we're just going to break

out of this loop.

and so we can come down here

and we can just print out

a success message so I could say

you win

because they got the secret were

since they have very very simple program

but

this is essentially all of the code that we need to be able to build a game

like this so

let's go ahead and play our game we can run it and

see how he did so I'm gonna

click play.

and down here you can see it's prompting us to enter a guest's so I'm just going to type in some

you know random texts

we can type in whatever you want.

and as long as we're not entering that secret word it's going to keep prompting us to

enter different information.

but

if I enter in the secret word

so if I enter in draft.

now

all of a sudden the programs can terminate and it's going to say,

hey

you win

because we were able to guess

the secret word.

so that's like

a really cool way for us to be able to do this.

and we actually have a fully functional guessing game.

but

I think this guessing game could actually be improved quite a bit.

a lot of times when

we're making a guessing game we want to set a limit

so in other words I want to set a limit for

the number of times that the user can try to guess the word.

so let's say that the user has

three tries right they have three guesses in order to guess the word.

and if they can't guess the word after three tries.

then they're going to lose the game.

but

if they can guess the word

inside of three tries then

they'll win the game right.

I think that will be a little bit more of a fun game so

why don't we try to program

that game,

basically we're going to set a limit

on the number of

guesses

that the user can have

in order to do this and we're going to have to create a couple more variables down here.

in other words

we're going to have to store a couple more pieces of information.

the first piece of information I want to keep track of is

how many times the user

has guessed

right,

so we can just make a variable called guests

cao

and we'll just set this equal to zero because initially

the user won't have

guest

down in this while loop.

every time we go through the loop,

I want to increment that gas can

write so every time we've gone through this while loop

I want to

increment that count because that means

the user will have guessed

so down here I'm going to say.

guess

count

plus

equals one

and this is just going to add

one to the gasket actually whips.

so

after each iteration of this loop we're going to go ahead and add one

to the gas count

right so that's the first variable that we're going to need we're also going to want to

store another variable

and this is going to be called guess

limit

and basically this is going to tell us how many times the user can guess the words on it it's going to be guests

limit

and

will basically just say three so let's say that the user has three tries

to guess the word three strikes and you're out so

the user if they can't get it in three tries

then

we're going to

basically say that they lose the game.

and I'm also going to need one more

variable here,

which

we're going to call

out

of

gases.

and

I'm just going to set this equal to false initially.

so this

out of gases variable is going to be a boolean.

and it's gonna tell us whether or not the user is out of gases.

so if out of gases is true

that means they have no more guesses right they basically lost the game

and if out of guesses

is false that means that they still have some guesses left so they can keep playing.

so let's use these different variables in order to

make our program or functional so

the first thing I want to do is

when I go through this loop.

I want to check to make sure that the user has more guesses,

right

in other words before I let the user

enter a gasp.

I want to check to see that they haven't already used up all their guesses.

so down here

I can make an if statement I can say

if

and inside of the condition I want to check to see that

guess

count

is less then

guess

limit

if gas count is less than guess limit.

that means that they haven't

guessed

the

total number of guesses that they have so they have some guesses left.

and

if that's the case and if that's true,

then I'm going to go ahead and

give them a guess and then we'll increment the guest count.

if this isn't true in other words,

if they

have reached their guests limit,

then I'm going to want to set

out

of

guesses

equal to

true

because there are guesses right they have no more guesses because

the gas count wasn't less than the guest limit.

and so that means that there are two gases so they have no more gases.

so there's actually

one more thing we need to do inside of this while loop

we need to

add another condition

onto this loop guard.

so right now we're going to keep looping as long as the guest

is not equal to the secret word

but remember

if the users out of gases in other words if they've reached their gas limit

we don't want them to guess anymore,

right so if they ran out of gas is then

we want to basically break out of this loop and not give them anymore guesses so

I'm going to go ahead and add another condition onto here

and I'm gonna say

wow

they haven't guessed the secret word

and

they're not

out

of gases so it's going to be not

out

of

guesses,

then

we're going to keep looping so as long as they haven't guessed the word and as long as they still have some guesses laugh we're going to keep looping

but

otherwise

we're going to break out of the loop.

and so down here

we're printing out you win,

but actually when we break out of this loop,

there's going to be two

possible scenarios.

so again,

there's two possible ways that this loop could andrei

either the gas is equal to the secret word.

so either the user guests of the word correctly,

or

the user ran out of guesses

and so

there's two situations down here

that we need to account for.

and so I'm going to use an if statement to figure out

which

is which I'm going to say

if.

and we're just going to say,

out

of

gases,

and,

if the user is out of guesses

that I want to print,

you lose

so we're basically going to be like

you lost the game.

otherwise though

if they're not

out of gases.

that means that they guessed the word correctly

so we're just going to pronounce

you win.

all right so now we have all the logic for this little guessing game set up

and let's see if we can run it and play through it so

I'm just going to run this program.

and now it's going to tell us to enter a guess

so why don't we

enter more guesses than we have so we're going to try to lose the game so I'm going to enter one gas

two guesses.

and now I'm on my final guess so if I don't get it here,

we should actually lose the game.

and you can see it says

out of guesses you lose.

so we were able to guess it

in the number of trials that we had.

let's run the program again

and we'll try to win the game.

so

we'll get a couple wrong.

let's say we're on our last gas and unlike

okay I can do this

so I type in the word and

bam

we won the game so,

that's how we can basically create a game where we have

a guess limit

so

this is a lot of code

let me walk you guys through this one more time

so you can just get a full understanding of what we're doing

up here I created a few different variables

we created this secret word variable

and we created this guests variable.

then

we also created

some more variable so we created this guests

count variable.

and this just keeps track of how many times the user has

guessed

the word.

and you can see down here.

every time

we give them a gas

were incremental

the guest count.

we also have guests

limit

and gas limit is telling the program how many times the user can guess.

so before I go through this while loop the first thing I'm doing is I'm checking to see that the guest

count

is less than the guests limit.

in other words

do they still have some guesses

left

if they do,

then we're going to get the input from the user.

otherwise,

we have this

other variable up here called

out of gases

and out of gases is going to tell us whether or not they have some guesses left.

so this is equal to false.

that means they have some guesses,

if it's equal to true however it means

no more dice

no more guesses they are done

so they lost the game.

the last thing we needed to do is specify an additional condition up here.

so

we are going to keep looping through the code

inside of this loop,

as long as the conditions up here

are true.

so as long as they haven't guessed the word.

and

as long as they're not

out of guesses.

we are going to keep

looping through.

and so

when eventually the user does break out of this loop,

there's going to be two possible situations the first situation is that they ran out of guesses

and so we want to check to see if that's the situation.

I want to check to see if they're out of guesses.

if they are

will print out a lose message,

if they're not,

then they must have guessed it correctly so

they win.

and so that is how we can use while loops

and

if statements

and also variables

in combination with each other to build a pretty awesome

guessing game

in this tutorial on a talk show guys by using

for loops in python.

now a for loop

is a special type of loop in python which allows us

to loop over a different collections

of

items.

so a lot of times will use for loops in python to like loop through different arrays

or we can loop

over like the letters inside of a string or

we could just loop through like

a

series of numbers

so for lives provide a very specific purpose.

and the easiest way to kind of wrap your head around

why four lives are useful as it is for me to show you guys

a bunch of different examples so

that's exactly what I'm going to do,

we're going to look at why four lives are awesome so down here in my

text file and my a

python file.

I'm going to write out a couple different

for lives.

so the way that we create a for loop

is just by saying four.

and now what I want to do is specify

a

variable

and this variable is going to

essentially represent

a

different value

every time we go through this for loop

and you guys will see

how that works in a second but just know that this variable is going to

be used on every iteration

of our for loop,

and

each time

it will most likely have a different

value so

in our case I'm just going to call this letter.

and I'm going to save four letter

inn.

and now what I wanna do is I want to specify

a collection

that I want to loop over.

one

example of this would be like a string

so I can put a string in here I can just put like draft

academy.

and now I can just put a colon

and so basically what this is gonna say it so it's going to say for

every letter

inside of draft academy.

I want to do something

and so down here inside of this for loop

and again we need to indent this

we can put what we want to do with

each letter so let me just show you guys like basically what this is going to do so I can print out

letters I can print out this letter variable.

and it's actually going to print out a different letter

inside of this dropoff academy string

on every single iteration

of this loop.

so

I'm gonna run this program.

and

down here inside of my counsel you'll see that I'm basically printing out

draff academy so

on the first iteration of the loop.

I printed out the first letter in draft academy which was g

on the second iteration of the loop

I printed out

I

third was our fourth with

a.

so

I'm essentially just looping through

all of the letters

inside of

draff academy.

so I'm saying

for

each letter

in dropoff academy.

I want to print

out

that

letter.

and so this is kind of like

how for loops can be used we can define a variable

and that variable will change

on each

iteration of the loop right so on the first iteration of the loop.

this letter variable represented a g.

on the second iteration of the loop.

the letter variable stores

the value

I

excited

right so we went through

this entire string we were able to print

out

each letter.

so in addition to using this with strings we can also use this with other collections for example like an array.

so if I created in array up here,

let's call it

friends.

I'm gonna set this

equal to a bunch of different values so we can

put like a list of our friends in hearings zelig

jim

karen

and

kevin

instead of saying the letter why don't we call this

friend,

and I could say for friend

in

friends

and now will print out

the friend

so

over here I'm saying for

each friend

inside of this friends

array.

I want to print out the friend so now

we'll actually be able to print out

each

element inside of that array so not here you'll see

we're printing out gym

and then on the second iteration were putting out karen and on the third would bring up kevin tso,

and he was a loop through all of the values

inside of the array.

and

just so you guys know like

you can name this variable whatever you want so I could name

I could give this like any random name,

and if I want to access it though I have to access it using that

same

name

so we can loop through asking me like an array we can also just loop through

a series of numbers

so I could say

index over here

and again this can be anything I'm just gonna call index

so we could say for index

in

range

and then in here I can pass in a number so I can pass in like

ten for example.

and down here I'm just going to print out the index.

when I run this program,

you guys will see that

it's basically going to print out every number in the range

from zero to ten,

not including ten

so starting with zero it's going to put out zero one two three four five six seven eight

nine.

but notice that it didn't print

out

ten

so it's essentially just printing out all the numbers between

zero and

ten

not including ton.

you can also specify

a

a range of numbers so I can say for example like

three and ten.

and now this will print out all the numbers between three and ten

not including ten

so run this program,

and you can see we print

out three four five six seven

eight nine

ten not ten

so whatever value that you put

here in this second position

is not gonna get included in the range

and ranges can be

really is also for example I could use a range

to loop through an array just like we did before.

so if I wanted I could say something like for

index

in range

and now

inside of this range

I can pass in

the length

of

the array.

so

just so you guys know if I wanted to get the length of this array.

in other words if I wanted to figure out how many elements were inside of it.

I could just type out

alli end

and then inside parentheses.

the name of the array and so

this is going to spit out three because there's three elements

inside of here

right

kind of make sense.

so what I can do is I can say down here inside of this range function

I can just type in

eliane

and then

friends.

and so what this is gonna do is it's going to essentially give me

a range

between zero and the number of friends.

inside of this list

so down here I could actually type out

friends

index.

and this will allow me to access

each

individual friend inside of this list.

just like we did before but now I'm doing it with

a range,

so you can see I'm

typing out jim care and kevin so

actually

for each

iteration through this loop

it's basically going to be printing out

friends

zero

friends one

and then friends

too because

in heater were passing in a three

and remember whenever I pass in there it's going to range from zero

all the way up to that number

but not including that number so

that's another way that we can print out all the elements in the array

and

looping through something like an array is actually a very very common use case

for four loops.

but like I said we can you spoil hopes to loop through essentially any collection that we have so

we can loop through like a string that we could also loop through

you know something like an array so

this can be really useful and bats are the basics

of for loops

in

python.

and I also want to show you guys one more example just while we're here

so

why don't we go ahead and print out a range

up to

five

brace this would just be a simple program

you can use all sorts of logic

inside of these four lives.

so let's say that I wanted to do something special on the first iteration of the loop.

so I could say

if

index

is equal to zero

and

if the index to zero than we know it's the first iteration of the loop so I could do something special I could like print out

first

iteration.

and then otherwise we could just

print lake

not first so this would be an example of like

maybe you want to do something on the first iteration of the loop

and do something else on

subsequent iteration so if I play this

you'll see only on the first iteration is it

printing this out and otherwise it's printing out other stuff so

you

don't be afraid to

put some complex logic

inside of these four lives

because

it can really make your programs more powerful

in this tutorial I'll show you guys how to build an

exponent function

are an exponent function is basically going to allow us

to

take a certain number and raise it to a specific power.

so in python there's actually a really easy way to do this I can come down here and I could print.

we could say like

too.

and we can just do

two multiplication signs

and I could say three

and this is basically just going to be two

raised to the third power.

so

you can

see here I can just print this out and

we get a

cassettes

to cube

so

it's really easy to do exponents in python.

but I want to show you guys,

how we can use something like a for loop in order to create a function like this of our own sun will actually create an

exponent

function

that will basically do this and we'll use

for loops to do it

so

let's create a function.

something as a death

and now we need to give this

function a name so why don't we call it

raise

two

power

and inside of here,

I'm going to accept two parameters the first parameter is going to be the

base number.

and then the second

parameter is going to be the

power number so we're going to take the base number

and raise it to

the power number.

so

over here we can just

make a colon

now

inside of this function when you start writing some code.

here's the thing

inside the function we don't necessarily know

the value of this poem,

right

for them why have we knew

that we were just trying to like square this number or cube this number.

I could just return

like bass

num

times

basal cell

right

now it's square the number or I could keep the number

bass num

so right so this would be like the number cubed.

the problem is though we don't know like right off the bat

what this value is going to be

right this could change like the user can decide that.

so in order to write this function we're actually going to need to use a for loop.

and I'm sure you guys how it can use a for loop

to basically figured this out so

the first thing I want to do is create a variable and I'm just going to call it

result.

and we're just going to set the result

equal to one so we're gonna start this off at one.

now I want to create

a for loop,

so I'm basically just gonna say

four

and over here,

I don't want to specify like

a

index on aug eight index

in

and now want to specify a range

and arrange will basically

range us

through

a

collection of numbers.

so basically I want to

multiply the bass num

by itself,

as many times as the pound numb

specifies

right

over here I can just make this

a range

of

power

numb

right and so we'll basically a loop through

this for loop

as many times as pound them so eponymous two

will loop through it twice.

economists for will luther at four times

and every time through the loop will multiply bass num by itself

or actually you'll see we're going to multiply it by this result,

and so down here inside

this for loop

I can basically say

result

is equal to

result

times,

pacing up

this should actually give us everything we need to take this number

to the specific power so

the actual like

result

of doing the math

is going to get stored

inside of this

result

variable so

the first time through the loop,

we're just multiplying basin on by one

right.

and so now result

is going to become

the same value is based on

the second time through the loop so this would be if we were squaring the number.

we're basically multiplying resort by basin um again so it's essentially just

based on long times based on

the third time through the loop

we're multiplying result times bass num

so we're essentially just like

keeping the number so

that's essentially what this for loop

is doing for us.

so the last thing I want to do is

right here below this for loop

I'm just going to

return

the result

so

we'll be able to return whatever the result of raising the number to the power was

so let's come down

after this function and we're just going to call it so I'm just going to say,

actually will print out the answer so

save raise to power

and the inside of these pregnancies member we can pass two numbers so let's

raise three

to the second power so we're just going to square three and we'll see how this works

so

from the program

and you can see down here in the console were getting nine.

let's try something a little bit

crazier

drive three

to the fourth power

and will run this

aggregate

eighty one so that's

three to the fourth power.

let's try two to the third power

and were getting eight

yeah so that makes us

so

our raised the power function is working

just as expected and that is what he has to do it one more time.

so

inside of this function were taking in two pieces of input were taken in a base number.

we're taking it a pow number so that's like

the base number is going to be taken to the power number

I'm defining a variable here called result

and result is where we're going to store

the actual result of doing the math.

now we specify this

for loop,

and I'm basically saying that

I want to loop through this range of numbers.

when I put

pounha um here is basically going to range from zero

all the way up to but not including the power number silk

we'll basically loop through power number of times

that makes sense.

and then every time through the loop we're just multiplying result by

base numb.

and then we're just returning results so

that's the basics of building a

power function

and

obviously like

if you're just trying to take a number to a power in python it's really easy but

this kind of shows you like the internal workings right

for a function like that to work we would have to actually

type something out just like this,

and this tutorial I wanna talk to you guys about two different concepts

in

python.

it's going be a pretty cool lesson.

first thing I want to show you guys though are

two dimensional lists so down here in our

python file.

I just want to create

a

basic list

so I'm just going to call this

number grid.

and I'm going to set this equal to

a normal let strangers like this

now normally if we were creating a list I could just put in a bunch attributes and bunch elements right,

and now all of these elements are inside of this number grid lists everybody's happy.

but

another thing I can do

is I can make

all of the elements

inside of this number grid list

lists

so

the first

item

in the numbered list is going to be a list.

the second item and the number grew less is going to be a list

etc.

so I'm going to show you guys have to do that

I can basically just come down here and

why would normally put the first

element in the list

I can just create another array

someone's going to make an open closed square bracket,

and now

I'm just going to say one two three

and I can create the next item in my list

I can say

four five six,

and then let's make another item in this list.

I can say

seven

eight

nine

and finally we're going to put one more list inside of the number grid list

and it's just going to have

zero in it so

inside of this numbered red lips write this

high level overall list,

we have

four elements

in

all of those elements

are

themselves

lists.

so essentially what we're doing is we're creating a grid right

this grid has one two three four rows

and one

two three carbons

right

for rose

three columns and that's kind of like

why these can be useful as we can create a grid like

structure inside of python

using

two dimensional lists.

so this is a pretty cool list structure.

and I wanna show you guys,

how it can access

individual elements

inside of this list structure so

for example let's say I wanted to print out one of these values if they wanted to print out this one right here,

the way I can access it is by saying

number grid.

and

the first thing I want to do is make an open and closed square brackets

and in here

I want to put the

index of the row that I want to access.

so this would be like row zero

because it's the zero of element in the array.

this would be row on its it and exposition one

this would be row to row three etc so I could put

roses grow

and now

right next to this I'm going to make another square bracket,

and I want to put the

index of the column so

this would be like column one

column to column three.

so

I'm going to put it another zero

because this is at the

zero

index

of this first

array so

I've

been zero zero here.

now we can print this guy out to the screen

and you'll see down here

that we get that one

so I can also do this for like for this eight for example so this is going to be

zero one two

can be row two and

column one

and now we should be able to print out that

e.

so that's basically how we can access elements inside of this

two d

list.

the next thing I want to show you guys

is

a

nested for loop

nested poorly with the situation in mega said well we have

a for loop

inside of a for loop.

and I'll show you how we can use this nested for loop

in order to print out all the elements inside of this array so I've basically shown you guys on a parse through

a

two dimensional

list or a two dimensional array.

so basically we're going to create a normal for loop so I'm going to say four

and I'm just going to say row

in

number grid.

and I'm using the word row here because

I'm kind of seeing

these guys as rows right these are sort of horizontal rows

in our little grid

so for each of those rows for each of the

elements

inside of number grid.

I want to loop through so I could actually just print out

each row right now

and it's going to print out all the rows inside of this

list you can see down here

we basically just get exactly what we have up there.

but I want to be able to access

each of these individual

attributes

inside of each of these

array elements

so

we can actually create another for loop and am I put that for loop inside of here,

so now I'm going to say four

column

in a

row.

and basically what this is going to give us is

each

individual

column or each individual

element inside of these

arrays

so for example inside of the arrays that are

the elements of the number grid

over that makes sense

so

down here.

now we can just

print

out

column

and this should actually print out

every single

value inside of this two dimensional array.

so let's go ahead and run this program.

and down here you'll see that we're basically printing out

one all the way down

to

zero

so we're printing out all of the

elements

inside of

all of the arrays inside of the number grid.

so that's how we can use two dimensional lists and

nested for loops together in both of those things

are actually pretty handy in python

in this tutorial I'm going to show you how to build a basic translator in

python.

so essentially we can

take in

a strings we can take him like a phrase or a word

and will be able to translate it into a different language.

so

over here I have this little file

and it basically specifies this language

that I made up so I'm calling it the draft language

and

in the draft language

all vowels

become

g

so if I was going to translate an english word into

a draft word

for example the word dog,

I would look through the word dog

and

any instances where there was a vowel

so

in our case let's just say

a e I o u.

I would convert that vowel

into a g

so dog would map to

ddg

cat would get mapped

into

c g t.

so those are the basic translation rules.

obviously this is a pretty simple language but

you get the point any vowel is going to become a

g and then we'll get

the draft language.

so we're going to build

a draft

translator

over here in our

python file.

let's

start making this translator the first thing I'm going to do is just define a translate function.

so I'm going to make a function here and I'm just going to call it

translate

and

inside of these parentheses

we want this to take

one

piece of information which is going to be

the phrase

that we want to translate so I'm gonna say

phrase

and now inside of this function we need to figure out like

ok

how can we translate

english into our draft language well remember

the rules is basically just

any vowels become

jeez.

so the first thing I want to do is create a variable

and this variable is going to be the translation so this will be like the final result that we're going to return to the user.

so I can say

translation

for now I'm just going to set it

equal to

the empty string so this is just going to be like

a completely empty string it's not gonna

be doing anything.

and

now what we want to do is we basically want to

loop

through

every letter inside of this phrase.

and

if it's a vowel we want to change it to g

and if it's not avowal we want to leave it alone

and

we're

essentially going to be looping through phrase.

and we're going to be adding the letters

onto this translation

one by one so make sure you guys how we can do this.

I'm going to make a for loop somewhere safe for

and I'm just going to say a letter

in

phrase.

and so now

when I looped through here I can access

each

individual letter

inside of the phrase that they passed in.

so what I wanna do is I want to check to see if

the letter is a vowel or not

right.

if it's a vowel than we can

add

a g onto translation.

if it's not available

then we can just add on whatever

letter it was onto translation

anyway so

many users

if statement I'm going to say

if.

and there's actually this special thing we can do in python we can check to see if something is in

something else

so I can say if

letter

inn.

and over here I'm just going to take out all the vowels that was a e I o u.

and

a e

I

o to you.

I'm basically checking to see if the letter

is inside of

this string

and if the letter is inside of here,

then we know that it's

a vowel so

down here we can handle that case

so I can say.

translation

is equal to

translation

plus

g

because

if

this letter is a vowel we just wanted to convert it into a g.

otherwise though

I can basically just say

translation

is equal to

translation

plus

letter.

so in the case where we have a vowel I'm adding a g onto

translation

and the case where we don't have a vowel.

I'm just adding on

whatever letter it was on to translation so

finally down below this for loop

we just want to return

the translation so I'm just going to say

return

translation.

and now we have

a

awesome translate function

and it should

probably work so

let's come down here and we'll test it out so

we only allow a user to input some information so

I'm basically going to call this function.

actually we're going to print it out so

we'll print this out and I'm going to call this function

translate

and

inside of here I'm actually just gonna

pass

whatever the user

inputs

so

I can just say

input

and

inside of these parentheses I can say the problem so

enter a phrase,

and so now

I'm basically combining all these statements together I'm saying I want to print

out

the translation

of whatever the user enters in.

so let's go ahead and run this program

and we'll see how we do

so

I'm gonna run the program

it says

enter a phrase actually let me

format this a little bit better.

okay

that's it says enter a phrase.

so let's go ahead and do that.

so

let's just type in

the example we use before him and say dog

and so now out pops the answer which is

d

g g.

so that's kind of cool.

and we can just keep running this as many times as we want so I could type only.

to be or not to be,

this is like a little bit longer of a string,

and you can see

it translates it into our

draft language.

so that's basically how we can

create our little a translator out and that's pretty cool.

as you can see we're using a for loop

in combination with an

f loop and that's a really powerful structure

and actually there's one place over here where we can

make this a little bit more efficient so

instead of saying

if

letter in

this string.

you'll notice here I'm checking to see if it's in

all the lower case and the upper case.

I could actually just say if

letter

dot

lower

in

and now I only have to type out the lower case letters,

and it's still going to do the same exact thing so

that's a little like

hack

or whatever that we could use

and there's also one more problem with this program so

you'll notice down here

we're setting the translation equal to the translation

plus

g.

but the problem is if

I was to start

my word inside of the phrase with a capital vowel

so in other words if I said like

on,

you'll notice that when this gets printed out,

it gets printed out as lower case g and

so it's not keeping our

uppercase

syntax

and that's kind of a problem so

we can actually use another if statement in here

and we could check to see

if

letter dot

is

upper

and if the letter is upper case

then

we can just set the translation equal to

the translation

plus

a capital g,

otherwise,

we can just set it equal to the lower case g.

it's a now we're able to control

both of those situation so

let's just test this and see if it works

and to rephrase

say on.

and now we're keeping that

capital letter so

those are just a couple different ways that we could make this program a little bit better,

but the basic concept is we have a for loop

and then we have some

if loops inside of it,

and we're calling this awesome function that can translate a word for us

in this tutorial I wanna talk to you guys about comments in python.

this is going to be a pretty short tutorial I just want to give you an overview of what comments are and how we can use them in our python programs.

so over here

in my python program I just have this line here it says print

comments

are fun.

so if I run my program

down here inside of the council it's going to print out comments are fun right,

so any code that I put over here is

going to get executed by python,

but there's actually a special

line of code that we can write

and it's called a comment

and a comment is basically a line inside of our python file that's just not going to get rendered by python,

so in python sees it as just going to ignore it it's not going to execute its not going to print anything out.

it's just gonna kind of ignore it and comments are

basically just used for us humans,

so a comment is used for like me or another developer to

write a little comment a little like plain tax dino comment inside of a file

nor retreat of

a comment

I could use this

hashtag symbol.

so in click hashtag and now I'm

writing a comment.

so I can write whatever I wanted in here I could say like

this

program

is cool

and

you'll notice when I run the program

that doesn't show up anywhere.

it doesn't matter what

I put off at halftime

this is just like ignore by python,

it's just for me or another developer to come in here and use.

so a lot of times you want to write like a little note

inside of your python files or maybe you can write yourself a little reminder.

or if you want to write

a line to lay explain a line of code

to for example

I can write a comment that would explain

this print statement sighted sailing

this

prints

out

a string

right

now anybody looking at my file would be able to read this and they'd be like,

oh that's what this does ok

cool

so comments are useful for

leaving little comments in a python file

you want to make

comments on multiple lines.

you can just create a new line and use another hashtag

and so that I could type out whatever my next comment was

I mean generally if you're gonna put comments on multiple lines you want to just use multiple hash tags

plot

there's actually another way that you can write out comments

so you can use a triple

quotation marks so I'm typing out these single quote

and I'm typing not three times

so you can see here,

up here we have this three times we have this three times.

so in here I can you know write any comment that I wanted so I can

put you know

as much taxed up here as I would want.

and

same thing when I run this program.

it's just not going to get rendered so

this is another way to make

multiple line comments

but the link official python like style guides or whatever

just recommends that if you're going to put comments on multiple lines you used these hashtags so

you know you can really do whatever you want but if you want to be like super

python official then

use these hashtags

comments can also be useful for

doing something called commenting out a line of code.

a lot of times when you're writing a program,

you might have a line of code in there

that

is maybe like potentially making stuff up.

and so what you can do is you can actually comment

out that line of code so

I can put a comment in front of this line of code.

and now when I run my program.

the program is going to run,

but it's not going to use

this line

so sometimes if you're trying to see if like a line of code is

causing you trouble or if you want to see what your program would be like without a line of code

or even like a block of code,

you can just commented out.

and that way you're not actually deleting the code

from your file

you're just commenting it out so pythons gonna ignore it,

and those are really the two uses for comments as to write little notes

right little comments about different things

or to comment

out code and

as you go forward and python

I'm sure you'll find uses for

comments

in this tutorial on a talk to you guys about

catching errors in

python,

and a lot of times when we're writing python programs

you'll encounter of an

error so different situations could come up

and your program might throw an error or it might throw an exception.

and a lot of times when these

situations happen though completely stop your program from running.

and what we can actually do is we can watch out for

you know a certain specific errors that are going to

pop up in our program and we can actually handle them.

so instead of our program just breaking and stop executing,

we can actually handle those errors and do things when they occur so

I want to show you guys an example of using this down here I'm saying number is equal to

its

input enter a number,

basically what's happening is I'm prompting the user to enter into a number

using this input command

and then I'm converting whatever they entered

into an integer.

so as long as they enter in like a valid integer I can convert it into an integer.

so I can convert it into like a whole number

and I can store it inside of this number variable

that I'm just printing it out so let's try to execute this program,

I'm going around the program

and you'll see down here it says enter a number,

so we can enter in like four for example

and when I answer in four everything's going to work and it's just going to print out four and

everything is right in the world.

and actually I'm going to modify this appears it's a little easier to see.

but what if we run the program again.

so it says okay enter your number.

let's say that I break the rules might don't enter a number so it is ignore what the prompts says and I put

you know

some random text in here,

now when I enter this

the program's going to throw an error,

you see down here it says value error

invalid

literal for ants

base

with basten

basically

paved and answering

an integer like

you said you would

write.

we told them to enter in a number

they entered in text

so it broke the program.

and

this is a situation that happens a lot so there's a lot of them in situations where something can just go wrong in our program.

and up until now we've just kind of accepted it as a reality

but

if you're writing a real live python program

you don't want something like this to trip up your program,

you don't want the entire program to break when somebody just forgets to enter in a number

right

you want to be able to handle all these different situations,

and

in order to handle them we can use

something called a try except block

in a try accept blog will basically allow your programs to try out

a piece of code,

and if everything goes well then we're great like

we could try out entering in the number

and if the user enters into correct number great,

but if they don't enter in the correct number then we can basically like

account for that so they entered it in something like a string when they're supposed to render in a number.

we could tell them like hey you entered in the wrong thing

so I'm sure you guys how we can use these try accept blocks are going to come up here

and I'm just going to say try

to make a colon.

and I want to indent.

both of these things.

so both of these things are going to be inside of this

try block.

now I'm going to make a new line I'm going to come down here and I'm just going to tape out

except.

and I'm also going to put a colon here,

and down here I'm just going to print something out so I'll just say like

invalid

input.

so now

since I put this code inside of this try block.

if the user enters in something wrong

it's going to be able to catch it so it'll be able to catch what the user does wrong

and print out

invalid input onto the stream.

so let's go ahead and run our program.

and it's just gonna say enter a number.

so we're going to ignore that will enter this end

and now instead of yelling at us in breaking the program

just says hey

invalid input.

so was able to handle the error they got called it was able to handle the invalid

input error

basically just told us hey

nowhere input.

so

this is a really powerful thing that we can do in our python programs

basically just to protect our programs

right

if I want to have my program running for long period the time

I can't have something as simple as an invalid

input

trip it up

so I can catch that invalid input using these try except

blocks.

but here's the thing you notice that this

little guy down here is getting

highlighted.

and let's just see what it has to say so it's basically saying

two broad exception clause.

and

this is a message that we're getting because when I just say accept

this will catch

any error under the sun so anything that can go wrong in my program for the most part

this is gonna accept it so

let me give you guys an example,

let's say I had in my program

I was creating a variable right so I'm

gonna

create a variable called

value and I set it equal to ten divided by the zero.

now if you know anything about math

you'll know that you can't divide a number by zero it's not possible.

so

the program

isn't going to be able to handle this and you'll see that this is going to throw an error for us.

so I run the program.

it basically says

zero division enter division by zero,

we're not allowed to do that right.

if I took this and I put this down and out of this try block.

and

I just pasted it in here,

it's going to get caught by this exception

that we wrote down here so it's going to get caught by that accepts and when I run the program

you'll see it says

invalid input.

but the problem is that we didn't

input something that was invalid

right

we just divided by zero

but it wasn't

able to handle that.

right so it could not divide by zero

it through an error.

so even though we didn't get an invalid

input even though it was because we divided by zero it's still printed this out.

and this brings me up to another point is we can actually catch

or we can accept

specific types of errors.

so for example

in this case we got a division by zero error

in this case we got

an invalid input air I we we

put something in that was wrong you

can convert the value.

so I can create two different except blocks to catch two different types of error so down here

I can just make a space and I can specify the type of error that I want to catch.

so when we divided by zero it was

zero division air.

so if I just put zero division error in here.

now it's going to catch that zero division later so I can say

divided by zero.

I can also make another accepts I could say

accepts

and

we can catch the other exception that we got so I think it was

a value air right now is

we put in the wrong type of value

inside of that

inputs so now we can print out

invalid input.

so

with these two except blocks were basically able to handle both of these

situations so

for example if

this ends up breaking the program this division by zero,

then it'll be able to catch that so down here it'll tell us.

hey

you divided by zero,

but if I was to get rid of

this line of code,

and

I just

entered in the number wrong

so I came down here and I answered in

a string set of a number.

now it's going to

tell us invalid input so

we're going to be able to specify

what happens when certain things break.

so when we get a valid it

when we get a value error we can say invalid

input.

when we get a zero division error we can say divided by zero and depending on what breaks depending on what happens,

we can actually

do different things,

and I want to show you guys

one more thing we can do which is

we can actually store

this

error as a variable.

so I can say except

I can say as

and I can type in a name here so a lot of times people will just say like.

ye are our

and down here

I can print out the actual error so I can just print

e r r.

and so if we end up dividing by zero.

so if I say answer is equal to ten divided by zero.

we're going to throw this error and it's going to print

out what went wrong so

now I can run this program

and it just says

division by zero

so it

just printed out

the error that we got.

so that's another useful thing you can do is you can actually print

out the specific error that got thrown.

now

a best practice in python is to use these

specific error so you always want to accept

and except for a specific

error

when you don't want to do is just say

except

and

then just accept anything under the sun.

it's this too broad

and

if not in good practice and pythons you wanna be catching specific errors like this

in this tutorial on a talk to you guys about reading from

external files in

python,

you know a lot of times in python you're going to want to

read

from files that are outside of your python file,

so you might want to read information from like a text file or a csv file or like an html file.

and

you can actually use something called the python

read command and it will allow you to

read a file

that is stored outside of your python file so you can use these files to get information or you can

parse through different files and do different things.

so I'm gonna show you guys the basics

of reading files

opening files closing files

doing all that stuff

over here I have this

file

called employees dot text

and it basically just lists out a bunch of different employees like

these can be employees in an office or whatever.

so it's just listing out all of this

information.

so let's say that inside of my app dot python file I wanted to read

the employees

inside of that file.

the first thing I have to do is actually

open that file from inside

python.

so I can use a special command

called

open.

so I can say open

and then

in here I can type in the name of the file that I want to

open so this is either going to be a relative path to the file.

an absolute path to the file or

just the files name if

both files

in the same directories on my case

app dot python and employees dot text

are in the same folder

within the same directory so I can just type out the name of the file liking to say

employees dot text.

and I want to put one more thing inside of this

open function,

and it's going to be the mode

that I want to open the file in

which you could actually open files in

a couple different modes

and the first mode is called read

so I just put an

r here and that's going to stand for a read

and this basically means that I only want to read the information inside the file I don't want to modify it I don't want to

change it.

I just want to read it I just want to see what's in the file and do some stuff without information.

another

mode is called right

so I can type in this w

and writing basically means that you can

change the file right you can write

new information you can change existing information.

there's another one called

a

and

a stands for a pen.

and it's basically means that you can

append information onto the end of the file so

you can't modify any of the information in the file.

you can't change any information

but you can

add

new information.

and there's one more which is

r

plus

and this basically means

read

and write so this will give you

all the power of reading and writing.

so in our case,

we are just going to be working with

regular are so we're going to be reading

from the file.

now this open function will essentially just

open

the

file so it's going to like

golden map file inside of our file system

opened it up

and it'll allow us to read through it

but generally we're going to want to store this

opened file

inside of a variable so

I can create a variable and we can just call it

employee file.

and I'm just going to set it

equal to this

open function.

so now the

open employees dot text file and

all the content inside of it

is stored inside of this

employee file

variable.

now

whenever you

open a file

you always want to make sure that you

close the file as well so

just like we have this open command

we also have

in

close

function so I can come down here and say.

employee

file

dot

clothes.

and

this is essentially just going to close the file so we're no longer going to be able to access it and

generally it's a good idea whenever you're opening up a file and you want to also make sure that your closing the file at some point so generally

once you're done reading it and you can just close it.

so that's kind of like how we can open and close the file.

now let's talk about how we can get information from the far right

there's no point having the file that we can't figure out what's in it

so

there's actually a few different functions that we can use

on this employee filed to figure out what's inside of it.

and I'm gonna show you guys

some of those so I'm just going to make a print statement.

and

inside this print statement will basically just print out some information

about the employee file so

the most basic thing we can print out is just the entire

contents of the file.

but before I do that I want to show you guys how you can check

to make sure that a file as readable.

so before we do anything else generally is a good idea to make sure

that it's possible to read this file.

and there's

a function

inside of python we can use called

readable so I'm just going to type out

in poorly file

dot

readable.

and

this is going to return a boolean value and it's going to tell us whether or not we can read from this file so I'm going to run my program

and you'll see down here we get a value of true

and that's because we set the file with

a read

mode so it's in read mode we can read from it.

if I was to put

a w here so if I put like right

now

redouble is going to be false because we can no longer read the file we can only write

to the file so

I'm going to

change this back to our so we can just read it.

so once you figure out whether or not the file can be read from

let's

actually read it so

there's another function called employee file dot read and this is basically just going to spit out all the information in the files

so when I run the program

it's just going to spit out

all of this

information right all the information isn't that was in that file.

I can also come down here and we could read an individual line inside this file so I can say employee filed dot

read line.

and what this is gonna do is it's gonna read an individual line

inside of this file so

now when I run this program you'll see it's just reading that first line in the file.

and this red line function is actually just

reading the first line and then it's basically like moving a little cursor onto the next line so

if I was to copy this line of code,

and then

printed again down here

I'm saying employee filed out read line.

so it's going to read the first line

and then when I say it again it's going to read

the line after that so this is actually going to end up printing out the first two lines in the file.

when I run this program you'll see we print out jim sales men

and dwight salesman.

so if I was to do this multiple times I could technically print out

every line inside of this file.

and you can see we can do that

and so that can be pretty useful for reading multiple lines in a file but there's actually another function that is better at doing that.

we can say instead of employee father

read line we can say dot read

lines.

and what this is gonna do is it's going to take

all of the lines inside of our file

and put them inside of an array.

and so now when I print this out you'll see we have this array down here it says

jim sales men that's the first item in the array

to white salesman

the second

item in the array.

it's basically taking each line and putting it inside of an array.

so if I want to access a specific line

I can just refer to it by its index in the array so if I said one.

now this is going to give us that

do white salesmen line

because that is at index position one inside of the array.

you can also use this reliance function

with a for loop

so I could come up here and create a for loop

is going to save four

and we'll say

employee

and

employee file

and then for each employee we just want to print them out so

it actually started

we have to put employee file dot

read

lines up here

and so now there's a loop through all the employees

in this employee filed out read lines array.

so we can actually just

print out

the individual employee

and now this will print out all the employees

inside of that files is basically printing out

each line in the file.

and that can be pretty useful.

so you can use all of these different functions like read read line read lines

readable you know there's a bunch of these different things that we can do to get information from a file.

and so there's a lot of cases where you're going to want to be able to parse through information in a file and this is a

awesome way to do it so

just to recap in whenever you want to open a file and read from it you can just use this

open function

type in the name of the file and then the mode,

which in our case is going to be r.

then you can do all sorts of stuff with it and you always want to make sure that

you close it when you've done that's just good practice so

that's the basics of reading from files and hopefully you guys can

use this in some way shape or form in the future.

in this tutorial on to talk to you about writing and appending to files in

python.

so one of the cool things about python is it allows you to work with

external files so I could have like an external text file and

I could actually like completely

read all the information in it I could pass through it

use that information to do certain things,

but it isn't a reading a file I can also write a file and that's what I want to talk to you guys about today's writing new files and appending onto existing files

over here I basically just have some code written out

and this essentially just

reads information from this employee's dot text file so you can see over here,

I am specifying the mode which is

r and that stands for read

and then down here under his reading

all of the contents of the file and spitting it out on the screen.

so I'm gonna click the play button over here,

and

you'll see that

if this executes so it's printing out

all of the

lines of code in our text file so over here I'm in this employee's dot text file

and it just has all this information like

employees in an office.

but let's say that I wanted to add another employee onto here

right ?

let's say that

a new

employee joined our company is that we wanted to add them onto this list.

well

I can come over here to my app dot python file

and

instead of

reading from the file

I want to

append it to the files I want to say

a

and appending to the file basically

basically means that you're adding

some text

at the end of the file so

wherever the file ends you're just going to add some text

onto there.

so what we can do is we can actually add another employee into the file.

so

instead of printing something

out I'm actually just going to say.

employee

file

dot

right.

and when I say employee filed out right I'm going to be able to write something to

the end of the file so

I can basically does right whatever I want so why don't we add in another employee

into our employees dot text file so we can add in another employee why don't we say like

toby.

and he's going to be in

human

resources.

so now

when I run this program.

it's going to add

toby human resources onto the end of the file somewhere on my program.

and

you'll see that nothing shows up down here in the council.

but if I go over to my employees dot text file.

all of a sudden

we have a new entry over here it's

toby

from human resource is right so I was able to

append a line onto the end of this file.

but here's the thing you need to be careful when you're writing to files because you can actually mess up a file

very easily

for example

I already added toby here into my file.

but if I was to run this program again,

you'll see that over here in this employee's dot text file

it when I hadn't

added toby again

right so it added this employee here

again

and also you'll notice that in this case,

these employee didn't go onto the next line

I accidentally ran my file again and all the sudden it messed up

this file over here

and so appending you really need to be careful because if you actually go under file again or have you

you know,

append something on something wrong to the file it's permanently it's getting saved inside of the file.

so I want to talk to you guys are a little bit more about you know

appending another thing we can do let's say we wanted to add another

employee

and you'll notice over here in this employees that text file

when I appended it on again

it got appended

to

the end of the existing line right

so the first time I had

a new line there but if you don't have a new line at the end of your file

and you all and you want to add a new line,

you're going to have to add some special characters

so let's add another employee

and we'll call her

kelly,

and let's just say kelley is in

customer service so

kelly is going to be in customer service.

and if I want to add

this employee onto the end of the file in a new line I'm going to have to put a new line character in front of it so I can say

backslash

n

and this will upend

this entry

into the file

with a new line so on a new line so now when I run this,

you'll see we get kelly from customer service

on her own line.

so you want to make sure that you're aware of like these special characters that you can use they call them

escape characters

and you're in time you're audi onto a file you want to make sure that you're adding on exactly where you want to add on.

so in addition to appending to a file.

I can also just like

overwrite a file or I can

write

an entirely new file.

this is as we already have this open instead of appending to the file.

why don't we just write

a file so I'm going to use this

w.

and now

if I say employee filed out right

because I'm using w and I'm not using

a,

it's actually going to

override

the entire file and it's only gonna put this inside the file so

when I run this

and we go over to this employee's dot text file

you'll see we only have one line inside of this file now it's just

kelley customer service.

that's because I was using double you

not

a when you use w it's just

overwriting everything that's in that existing file.

you can also use w to create a new file

so over here I could say employee file as he could to employees

one

dot text.

and now what's going to happen is when I run this it's going to create another file for me song in a run this

and

you'll see over here in my file browser.

we have this new file employees one dot text

so if I open this up.

it has exactly the same stuff as in this employees file,

but it basically created a new file for us and so a lot of times you're going to want to create a new file,

and you can use different extensions to so if I wanted to create like a web page

I could say

index start

each tier mel

and I could also add in some

each team malcolm here so

if you don't understand html don't worry about it but

if you do I can put like

a paragraph in year

another paragraph like

this is

html

basically ht mouth like a webpage.

and

the point I'm trying to make is that you can write out a webpage

inside of python by doing something like this so

now when I have played this

we get this

index style

html file.

and it has some

html inside of it so

that's one way that writing to files can be really useful you can

overwrite

an existing file,

you can write a new file and create it,

or

you can append onto the end of a file and

there's

tons of applications for writing to files and pythons and great language for

working with reading writing

doing all itself with files

in this tutorial on its altea guys about using modules in python.

now a module is essentially just a python file that we can

import into our

current python file so

for example if I wrote a python file that had a bunch of like useful functions are useful variables are you know other things like that.

I could take that file I could

import it into the file I'm currently working on

and I could actually access

all of those functions

all those variables.

all the stuff from that

external file

inside the file that I'm currently

working on so

I'm sure you guys how we can use module and then we'll talk about like

you know where you can find awesome modules and and really why modules make python and

awesome

language,

so over here in my text editor actually created this file and it's called

useful tools

dot python

and basically this file just has a bunch of

sort of like useful tools that I might want to use in one of my progress,

she'll see over here I have some variables this one is telling me how many feet are in a mile.

this one's telling me how many meters or a kilometer.

and then we have this list here which lists out all of the

members of the beatles,

am I also have a couple different functions down here so I have this get file extension function.

and this

basically just was

you know you give it a file name it'll tell you what the extension is,

and then we have this other function down here which

simulates rolling the dice

so you pass it a number

bypass it like a six it would roll a six sided dice

a passive

nine at roland nine sided dice etc

so

this is like a pipe on file that I wrote.

and it has some useful stuff in it,

and honestly there's a lot of stuff in here that I might want to use in the

other python files that I work with,

so let's say I'm over here at this

app

dot

python file and I'm thinking to myself,

ha,

I think I could use one of those functions

that was inside of that useful tools file

actually yeah

I need to

simulate rolling the dice in my program

well instead of having to go over here

copy this

function and then

paste it over here in my program

I can actually just

import

this

useful tools file

and I'll be able to import all of these functions and all of these

variables and attributes.

so the way I can do that is by coming up here

and I'm just going to go right at the top of my

file and I'm just going to say.

import.

and then I want to type in the name of the file that I want to import it so I was going to say,

useful underscore

tools

and pythons going to be smart enough to know that it should go off and

grab all the stuff from this useful tools dot

pi file

so once I've used that important statement

I can actually use all of the functions

inside of that useful tools file.

so

for example I could simulate rolling the dice I could say

useful tools.

dot,

and now I'm actually able to access

all of the attributes from inside that file so when I say useful tools dot

you'll see down here and my little suggestions menu it's telling me like beetles feet miles

get file extension meters and kilometers roll dice.

so it's giving me access to all of the stuff that was in that file so over here I could just say like

roll dice and we could pass this like a ten will roll a ten sided dice.

and

now this should actually

be able to run that function so

will simulate rolling a ten cited diet as you can see we got four

and

this is a really core concept in python which is

importing

functionality from

external python

files and this is like

huge in python and this is seriously going to change the way that you create your

python files

so

you'll notice like

I didn't have to

copy any functions or any variables or anything

over into this file and yet I was able to use

all this stuff that was inside this useful tools

file

so that is huge and honestly,

it's going to save you a lot of time because you can write something once and then you can

import it into your other files.

so that's really the basics of using modules mean modules are very simple module as any external python file

that you want to use some stuff inside of it.

I want to show you guys

a

place where you can go to find a huge list

of modules so

I'm going to go over here my web browser.

and

among this website

it's actually like the

official python docks

and basically all I did to get here was just typing

list of python modules and google,

and depending on the version of python you're using you're gonna want to make sure that you click the right one.

I flicked on the version three one

and over here on this page

you can see there's just a huge list

of python modules,

and these are basically modules inside of python

that you can just access so

essentially there's like

all of this awesome code that's

already been written for you and so if there's some sort of functionality that you want have inside of your python program,

chances are

there's a module in here

that has that functionalities of

all sorts of stuff

you can do I mean if you just look through this list like

you'll see a huge collection of

basically just

you know a bunch of

either python variables are python functions just

you know

things that you can use to make your programs better.

so

here's what I would recommend like

head over to this page and

to sort of look through a lot of these different module is no see what you can see

and honestly like

if you click on one of them it'll bring you to a page that

talks about like how to use they'll tell you like

how to import it and just you know

some basics about it

and this is sort of like the list

that on the official

python docs

but

he's using

the python community is huge there's tons of developers who use python.

and you can actually find a lot of third party modules so if you just go online and you know

look up like python module for doing actual

python module for doing why

chances are somebody out there has already written a python module to do what you're trying to do so.

if you get good at using modules and you get good at you know looking for them in finding them

you can actually save yourself a bunch of time because

chances are that somebody is already written a module to do

you know

what you're trying to do are like

part of what you're trying to do.

so now that we've taken a look at all these different python modules

I wanted to kind of dive in a little bit deeper into how we can actually use these things so

you'll notice here there's a lot of files right there's a lot of different modules that we apparently have access to in python but the question is

where all these files store

right

when I was over here in my program

for example I was using this useful tools

dot pie fire like

I knew where that was I created that file.

I was directly involved in making it

and I just imported over here it was pretty easy right ?

but what about all of these files

right

what about all these modules over healy

where all of these stored

and there's basically

two types of models here there's built in modules which means they're just built into the python language so

we can't just automatically have access to them.

and there's no

external modules

and

a lot of these external modules

are just stored in

basically the same

folder that we installed python on our computer so

for example let's look at a couple of these right we have on linking

base sixty four

bd be

been ascii like

if I come over here,

and you'll see I'm over here in milo file explorer I have my

python project which is draft.

there's also this other folder over here called

external libraries.

if I was to click down on this

and I come down here

you can see it's just

the version of python that I'm

amusing.

there's a folder here called lab

and this is a very important folder and this is basically storing all of those

external modules so you can see if I scroll down here

we have all of these different

like modules right

so here's that base sixty four hears bd be right.

a lot of these external modules are stored

inside of this lib folder and

like is that there's no external modules there's also a few modules that are just like a built in

modules

that are not can be stored inside of here

and you can actually tell so

for example if I was to come over here and click on

base sixty four.

it tells me where the source code

so the source codes in lab forward slash

base sixty four.

we are able to see that right how is I saw that inside of my lib folder

this been ascii though for example if I click on this,

you'll notice that this

isn't

giving me a folder cause this is basically just like built in to python so we don't have to worry about

you

lucky enough I'll just kind of like

it just how it works.

so some of these are external some of them are built in.

and

I want to show you guys

are

in addition to using these modules races.

there's a lot of good stuff here and honestly you could spend.

you know for years and years just learning about all these different modules.

but a lot of times you're going to want to use modules that

other people have written

and

you know

there's a lot of

developers

who work on python and who write different modules so there's a lot of useful modules either that aren't included

in this list right they're not going to be inside of this lib

folder

by

default.

and what we can actually do is

we can install those external module is as third party modules

that don't just come

preinstalled with python,

and I'm sure you guys haven't do that really quick so

the first thing you need to do obviously is find

a python module that you wanna installed you can download

and I have actually used one in the past.

python docs it's an

external module that you can use to

basically use python to create where documents which is pretty cool as you can like

format where documents inside of it so I'm just going to look that up here

in google.

I'm just gonna type in python

docks

and

here's a thing there's tons of these

extra modules you don't have to use python dogs.

I'm just giving you guys an example

but really it he just look up like

useful third party python modules there's going to be lists of hundreds of these things online

or in my case though

python docs has a website

and it basically just

has like some installation instructions are gonna come over here

and it tells me that I can install python docs using the command pip

install python docks.

so this brings us to

something I want to talk to you guys about which is a

pip

and pip

is essentially a program

and actually if you have a newer version of python three it comes preinstalled with python three

and you can use pipe to install python modules.

it's referred to as

a

package manager

and a package manager basically just allows you to like

install manage

update and uninstall like different python

modules

so pip

is extremely useful.

and in order for us to install python docs we're going to have to use pip

somno sure you guys are how we can do that,

but what I want to do is open up the

command prompt or the terminal on my computer.

if you're on a mac you wanna open up your terminal.

if you're on a windows computer you want to open up your command prompt

I'm using a windows

right now,

so I'm just going to come down to the search bar and type a and c m d

and this command prompts you to come up so I'm gonna click this

inside of the command prompt we can actually use

pip

firstly we want to do is check to make sure that pips install

and like I said if you have a newer version of python three pictured calm just

pretty installed

and it should do some work in here if you don't have a newer version of python three though,

you might have to install

pip

separately

and there's tons of instructions online and how to install pip.

so I'm just going to check to make sure that I have

to type in

pip

haven hyphen

version,

and they should spit out the version of pip

that I currently have.

so as long as we have to

pip

then we're ready to install an

external or third party

python

module.

all I have to do is just say pick

install

and now I just want to type in the name of the python module so in the case of python docks.

it was just

python dogs like that.

now again

you don't have to install python dogs

I'm just doing this for

this tutorial just going to show you guys

how this is going to work.

but you know

what you want to do is go online and look up some

third party external python modules,

and generally like

I'd say ninety to ninety five percent of the time

you're going to be able to just install them using pip.

in the off case that you can't install them using pip,

chances are they'll be like some detailed installation instructions but out say

for the most part any late

legitimate

python

module is going to be able to install using pip.

so

over here to understand a pip

install and add a module name so

python hyphen docks

and when I click enter this is going to go off and install python dogs for ourselves,

we

enter

and it's going to go off and install everything we need for python docs.

so you can see we have

successfully installed python docks

zero point eight point six,

so

I'm sure you guys

where exactly this god

placed so

normally when we install

a

external

third party module.

it's going to get put inside

this limb folder.

but it's gonna get put inside of a special folder in here called

site packages

so slight packages is a special folder and if I open this folder,

you'll see now we have this

docs folder and we also have this

python dark zero point eight point six

pi three points sakes thought eg info folder so

these two folders

are basically

included in that module installation so

you can see this docs folder has a bunch of different python files and

has a bunch of stuff in here that we can use.

so if I wanted to use this inside of one of my programs

I'm just going to refer to the name of the module so in our case,

it's just going to be docks.

so I used python docks

in order to install it but

we're going to use docs if we want to import it so

I could come up here and I could say

import

deal c x.

and

now I can actually use it so I can just say like docs dot whatever and you can see there's a bunch of different stuff down here.

there's like a document,

document part image part there's a bunch of stuff that we can

use with this and obviously

depending on the python

module you install

there can be different instructions.

but you can see it

got stored down here in this

site packages folder.

if I wanted to remove this

I could use

pick to do it so I could just say tip

and install and we could just

again saying

that a module names of

python dogs

and people now

and install this

on our computer.

so if I was to go back

over to this

folder,

you'll see that those two

that docs folder and then that

other

folder disappeared so they're no longer here,

and I'm actually not going to be able to use this anymore so

that's sort of the ins and outs of using

modules now again

there's tons of these modules and

I can be dozens and dozens of python

courses covering each one of these modules,

you know

the built in modules the

modules that are included by default and

external modules.

there's tons of these things out there

and really as a python programmer now what you can do is you can go out and play around with these different modules.

I showed you the ins and outs of installing them and you can use pip

to install all these different modules

and you know you can make sure that you have owned by checking the site packages folder or the lips folder

but really now it's on you to just come and go out and

use these modules and don't shy away from this because modules are a huge

part of python

you're definitely going to want to include them in your python stack.

in this tutorial on a talk to you guys about classes and objects in

python

classes and objects are

extremely useful in python programming and they can help you to make your programs

more organized and more powerful.

so

when we're in python we're dealing with all types of data

right

and a lot of times when we're writing programs we're going to have to work with different types of data

and there's essentially like a few basic types of data we can deal with usually things like

string cilic plain tax

numbers and boolean values those three are kind of like

the main types of data that you're going to be working with in

python and we have all sorts of structures we can use to store that data you know

things like lists or dictionaries.

but here's the problem

is that

not

all

information not all data not all things

can be

represented using

strings numbers or bullion's right,

there's a lot of

things in the real world that we can't represent in automating a string or an array,

or just a number right

in other words something like think of like something like a phone

or a computer

or a person

right you can't really represent those things

in like a string or a number you know it

in other words like

the data types that we have available to us in python

can't cover that.

and so what we can do with classes and objects is we can essentially create our own

data types.

so I can create my own data type for anything I want

python so

I could create like a phone data type

and it could represent a phone so I could store all the information I would ever want to know about my phone

inside of that data type in

and python we could create a class for it and

essentially what a classes is just saying hey

here's another data type that we want to use in python.

so with a class you can essentially define

your own

data type and its

super awesome and classes are extremely useful

causes are used in almost every single major programming language out there so

in this tutorial I just want to

give you guys a basic introduction of

classes and using them inside of python so

let's say that I'm writing a program,

and I want to

represent

a student

inside of this program so maybe I'm writing a program for like a college or a university.

let's say that in this program

I want to

model a student

like I want a model a real world objects and I wanted to be a student

right where we don't have a student data type

and I can't really represent a student in just a single string or a number.

so I can actually do is I can create a class

for a student and I'm basically creating like a student data type.

so I'm sure you guys how we can do that and create our student class

it's over here.

I'm just gonna make a new file.

wouldn't we get a new pipeline vase I'm just going to call it student dot pie

and

inside of this student dot pi file I want to create

a student class.

so the way that I can do that is just by typing

class.

and now I'm gonna type

the name of the class

that I want to create.

so in our case we are going to create a class called student so I'm just gonna say student.

and now we're going to make

a colon

now everything that goes inside of here

is going to be inside of our student class so

everything that's invented like this

will be considered a part of our

student

class

and basically what we can do inside of this student class is we can define a bunch of attributes

about a student.

so essentially what I'm doing is unlike modelling

a student I'm creating our student data type.

and I can use things like strings,

integers and bullion's

in order to

map

out what a student should be in what a student should have.

so I want to create something called an initialize

function.

and the way I do that as just by

typing out a d e f

and I was going to take

two underscores,

and then the word

I am I t

and then two more underscores,

and

you also want to type out

open close parentheses

and inside of those parentheses we want to type out

self,

and I'm on a colon after that.

what I can do inside of this initialize function

as I can basically map

out

what attributes a student should have

so we can essentially define like

hey,

here's the student data type

in

python

so what I want to do is add in

certain attributes

after this self so I'm just gonna say self

a comma.

and now we can start thinking about

you know

what values will

represent a student inside of our

python programs so

if I'm thinking lake

unthinking something like name

right so every student

in our programs should have a name.

they also might want to have a major

because they're in college,

they probably also will have a gps,

so their grade point average like

how they're doing in school

and lets to find one more thing that let me think,

why don't we make

a bullion

and it's going to be called

is

on

probation

and this will basically tell whether or not the student is on

probation.

so

essentially what I'm doing inside of this

initialize method inside of this

innate function is

I'm defining what a student

is

in our program.

and so in this program

a student

has a name,

it has a major

as a gps,

and it has a value that determines whether or not it's on probation.

this right here is the student data type.

so if I'm representing a student inside of my program now,

it has all of these attributes

associated to it.

and that's basically what I'm doing up here

now

inside of this initialize

function we actually have to do something and

basically what I want to do is

assign some values

so I'm going to be writing out some stuff and this might not make

total sense

right now.

but this is going to make sense in a second after we create our first

student

object.

so

just stick with me right now and just basically

know that we have to do what I'm doing over here so I'm just going to say self dot meme

is equal to name.

and then I'm going to say self dot major

because you get the major

self dot gps

is used

the gps.

and I'm going to say self dot

is

on

probation is equal to

is on probation.

so again

this might not make a whole lot of sense

right now

but

in a little bit

this is gonna make

total sense

so

now that I have this student class defined

I can actually use this class

inside of my other file so

I'm gonna come over here into this app

dot python file.

and this is just my main file.

so I actually want to create

a student right so

in that student class we defined

the student data type and we basically said like hey a student has a name,

a major a gps and

it says whether or not they're on probation

dots like the template for what a student

is,

but we can

actually create

a student so we can

create an actual student and give it some information.

and that's called an

object.

so

this

student class over here

is basically defining what a student

is

so a class is just like

an overview of what the student data type

is

an object

is an actual student

so it's an actual student with a name a major and a gps.

it's not just this template anymore it's

actually like a student that we're representing inside of our program so

in order to use that student class and create a student

object I actually need to import that so

all I have to do over here just say

from

student

and this is referring to this

student file.

I can say

import

student

and basically what this is saying is from the student

file.

I want to import the student class.

so even though these are both student they're referring to different things so this is referring to the file.

and this is referring to the actual student class.

so now that we did this we can create a student so

you can create an

object of a class

a lot like you would a normal variable so

I can just give it a name

I'm gonna call this

student one

and I'm going to set it equal to

student

and I'm gonna make an open and close parentheses

and now

inside of this parentheses.

I want to give this student

a name,

a major

a gps

and ann

is on probation

value.

so I'm going to say it will just create a fake student saw to say his name's

jim

and he's studying

business

and

we want to give them a gps and maybe has like a three point

one.

and

finally we want to say whether or not this student is on probation so why don't we say false.

so basically what I'm doing is I'm

saying that I want to create

a student.

so I want to actually create a student

object and rubber an

object

is just

an

instance

of a class.

so the class is like an overall template it defines what a student is

put an object

is an

actual student with

actual information so

we could call student one now

this is a student

objects.

so I just want to show you guys,

what this student object actually is and what we can do with it and then I'm going to talk some more about that

in it function

from before so

over here I'm just going to

make a print statement

inside of here I just want to print out

student

and

what's cool about

this

student one object is I can actually access

each of the attributes from inside of this object.

so if I wanted to get the name of the student I could say student one dot name

and now

this is actually going to print

out the student's name.

so over here,

you'll see it prints out

jim

if I wanted I could print out the students

gps

and it's going to print out the students

gps

three point one.

so now that I created this

student

objects.

I can actually access the information about the student

so essentially I'm just created a student

data type

so I could create as many of these students as I wanted if I wanted I could create another student we could call it student too.

and

essentially we do the same thing we just give it different information so

we could say lake

pam

and her major is

art

and she has like a

two point five.

and let's say that she is on probation.

so now I have another student student too so if I wanted

I could access information about that student we could say like student to dodgy p a

and now this has given me

the dpj of

student too.

so basically what I did was I created a student data type

and I created student objects

and now I'm able to represent a student

inside of my program.

so

let's talk real quick about all this stuff over here because I didn't really explain it

basically what's happening is

when I come over here and I say student

and I'm passing in all of these different values.

those are getting passed into this

init function.

so remember I passed in a name

I passed in a major at passing a gps.

when we create that student

we're actually calling

this function.

and when I pass in the name

the major and the gps

those values are actually getting stored over here in this name.

this major this gps

et cetera,

right

so I'm

giving this

student object.

all of that information.

and down here.

what I'm doing

is I'm

saying

self dot name

as he put the name

and basically what this means is

the actual objects name

is going to be equal to the name that they passed in

so self dot name as an attribute

of student,

raises the student is storing a name the student is storing a major the student is storing and gps,

but that's different from

this name

this major in this gps

remember and these are all just values that I passed in

there just parameters.

so I need to take the values that I passed in

and I need to assign them to the actual attributes of the object so I need to say

ok.

the name of the student is going to be equal to the name that we passed in

one more time.

the name of the student

objects

is going to be equal to the name

that we passed in

the name of the student's major,

is going to be equal to

the major that we passed in

the student's gps

is going to be equal to the gps that we passed in.

that's basically what's happening here so when I say self

is referring to the actual object so

over here what I'm creating this

student object.

I'm giving it all of this information.

it's taking that information and storing it as attributes

for

the object.

so

hopefully that makes sense I think that's about as clear as I can make it but

the point is that now we have a student

data type.

so now I can represent a student

inside of my

python

program

and that's like a super powerful.

and what's cool about classes and objects as you can do this with anything.

so in this example we created a student class and then we created student objects off of that.

but I can model

any real world entity

into this program I can model something like a phone

or I can model like

a water bottle

or I can model

you know

a keyboard

or I can model anything that I wanted.

inside of my program

I can just give it certain attributes right

so that's what's cool about classes we can model real world objects.

and we can create our own

data types

in this tutorial I'm gonna show you guys

how to build a multiple choice quiz in python.

so basically we're gonna

set up a little multiple choice quizzes and we'll have the user take the quiz and as they take the quiz

will keep track of their score and then at the end will tell them how they did so

this is going to be a pretty cool video I'm excited to show you guys how to do this and we'll get to use things like classes and

if statements

and loops

in order to build these programs are we're going to use a lot of cool

stuff in python.

the first thing I want to show you guys

actually did this before I started the video it's

this little a ray is called question prompts.

and I basically just wrote out all the questions that are going to be.

or I should say the questions I wrote out all the question prompts

that are going to be inside of my multiple choice quiz so the first one just says

what color are apples and the answers are

red,

purple or orange.

and the next one is

what color of banana is the options are

teal magenta and yellow,

and the third question is what color are strawberries and the

options are yellow red and blue so this is obviously a very very easy multiple choice quiz but

I just kind of

wrote out the questions beforehand so I didn't have to spend time doing that.

so let's talk about how we can build

a

multiple choice

test.

well.

the first thing I want to think about is how can I represent the questions in the test

right

over here we have the question prompts.

but there's actually two parts to a question when you think about it,

there's the prompts in other words like

the

actual question itself.

and then there's the answer to the question in both of those attributes needs to be

kept track of

right

I need to keep track of what we want to ask and I need a cap to keep track of what the answer is.

so what I'm actually going to do is create

a

question class

so I'm gonna create a little data type for questions

and inside of that question class will be able to store

the question prompts,

and will also be able to store the question's

answer,

so I'm just gonna come over here to my folder and I'm going to make a new

python file

and we're just going to call this

question

dot

p y so we'll call a question up high

and inside of this question dot pi file I'm going to make a class so I'm just gonna say class

question.

and I'm going to put a

colon here.

so inside of this

question class we want to define it and initialize

function so

I must say deaf

to underscores

in it

too underscores,

and

then we're going to type out an

opening close parentheses

self

and that a colon.

so after this self we wanted to find the different attributes

that will describe or that will

be included in a question so

we're going to include a

prompt

everyone to include an answer so every question we'll have a question prompt

and a question answer

now down here I'm going to take those values and assign them

to

the actual

class objects only to say self

dot

prompt

is either the prompt.

and I must say self dot

answer is equal to answer.

so now we have a question class set up and we can store all the information we need

about a question.

so what I want to do now is go back over to my app dot python file,

and we're actually going to create an array of questions.

so I have over here these three prompts,

and I'm actually just going to create another array so we'll just call it

questions.

and I'm going to set it equal to

to open or closed square brackets

and we're gonna start creating question

objects so I can just say

the first element in this questions ray will be a

question,

and we want to pass

questioned prompts

zero.

and the answer to the first question was

a

red green and that's the color of apple so I'm gonna pass

that first question.

and I'm also going to pass

the answer which is a,

and you see down here I'm getting an error so

seeing unresolved

references

question

so actually what we need to do before we can

create these questions is we need to import this question class on mckillop been here

come up here and say

from

question

import

question

so now

down here in this questions array we're

not getting that hair anymore so we created one question objects.

and I'm just going to

create a couple more for

these other ones

so

I'm just going to copy this one

and

we will pace this down here,

or it's an hour creating

two other questions in these ones are going to be

one and two.

and the answer to the second question is

c.

and the answer to the third question I think is that the

new york

yeah

so it's

cmb.

so essentially what we're doing is we're creating

three questions.

each one is getting a different question prompts,

and they're each getting different answers so now we have an array of questions that we want to ask

on our test.

so the next step is to actually write a function that will run the test right

it has to ask these are the questions and it has to check to see

if they got the answer right so

down here

lower in the file

let's create a function.

so I'm just going to say

death.

we'll call this run

test

and

inside of his prentices

were going to take one parameter into this function.

we're going to take

a list of questions so

I'm just going to say questions.

so this is basically going to be a list

of question objects that we want to ask the user.

so once I've been here

all I want to do is a loop

through all the questions so

I want to loop through each question

I want to ask it to the user.

I want to get the user's answer and I want to check to see if it's right,

and we need to be able to keep track of how the user does through the test so I'm gonna create a variable called score

and I'm going to set it equal to zero,

so every time the user answers a question right will increment this

score

variable

right so what I want to do is like I said loop through all the questions in that questions array so I'm going to create a for loop

I'm going to say for

question

in

questions.

so in other words for each question object

inside of this questions array.

I want to do something.

and

basically the first thing I want to do is ask the user the question

and I want to store their response inside of a variable.

so I'm going to say

I wanna make a variable down here called

answer.

and this is going to represent the

user's answer to the question.

and I'm gonna

set it

equal to

input

and I need to give this a prompt

so

I'm actually going to give this the prompt for the questions I can just say

questioned dot

prompt.

so now I have

the answer that the user entered in which is stored inside this variable.

so we want to check to see if they got the question right.

and I can do that using an

if statement so I can say

if

answer

and this refers to the student's answer

is equal to

question dot

answer

so I'm checking to see if the answer that the student

gave

as equal to the answer of the current question

that we're

asking.

and if this is true,

then I just want to

increment score so I'm going to say score

plus

equals one and this basically just means we're adding one

to the score.

so the last thing I want to do inside of this function is just

print out

the results I want to print out how the user did

so down here I'm just going to say,

print

and I'm basically just going up are not like hey you got like

two out of three questions are you got five out of six questions right

or you got zero out of ten questions right well

what does per not how they did so

to say to you got.

and now I want to print out how many questions they got right

so this is just going to be this score.

and in order to print

a number alongside of a string like this I'm going to have to say s t r,

and then type in the number so say

str score

so basically say you got

however many they got right

out of so we use this little

forward slash.

and

now we'll just say

how many questions there were so we can say.

and then I'm going to have to convert this to a string because it's going to be in numbers we can say string

and then want to figure out how many questions were in that questions array so I can say.

ellie ann

and inside of here we can just say

questions

so this is kind of like

this

long state and just to turn out how many questions that were

so that over here to say

correct.

so now we have this print statement.

and it's just going to be printing out how many questions they got right.

so let's see if

this works the last thing I need to do is just call this

run test function so I'll say

run tests.

and I'm just going to pass it that

questions are ready to be created before so

we created this questions array with all of these question

objects inside of it.

I'm basically just going to pass that into this run test

function.

so now let's run our program and

see how we didn't hopefully

we don't getting errors.

there's a lot of code there so

it's possible that we might.

okay so this is what color are apples has a tough one I once put

a.

so we'll get the first question right ?

what color are bananas.

let's get the second question wrong

so I'm going to say

be bananas aren't magenta

and we'll get the third question right so it says what color are strawberries

output be cassettes the right answer,

so now

you'll see that our program prints out

you've got two out of three correct.

so not only did to ask us all the questions and get our input for each question

but it also kept track of

our score and it printed it out so

why don't we run through the tasks one more time.

and

we'll just like

get two wrong this time so we'll get this one wrong I'll get this one wrong and I get this one right.

so now it says

you got one out of three correct so

say would actually great our test.

and

what's cool about the program we just wrote is

if I wanted I could add another question into here

and it would

automatically be able to ask it so it doesn't matter how many questions we put in here

it's just able to ask

so

really the point I was trying to make with this whole video was just how we can use something like a class

in order to

model a real world

entity.

so for example

we created this question class.

and we were able to store all the information

about a question that we could ever needs were ill bizarrely the prompts and the answer,

so we created our own question

data type

and then we were able to create a bunch of different questions,

pass it into this ron test method,

and it was able to grade the test and just run the test

really easily so that's kind of the point.

so hopefully this makes sense.

you know this was a lot of code

so if you don't fully understand what I did go back watch the video you know,

try to cobble times on your own and see if you can create your own multiple choice test

in this tutorial on talks you guys about

class functions

in

python so

a class function is essentially a function that we can use

inside of a class and it can

either modify the objects of that class where it can

give a specific information about those objects.

over here I have this student dot pi file

and

inside of here I created a student class I was headed class student

and I gave this student

a couple of different attributes I gave it a name,

a major and a gps

so I can give this student.

all of this information so when I create a student objects.

it'll have

all of that information

in it.

now over here on this

app dot pi file it actually created to students

so

student one is

oscar who was studying accounting and has a gps unit three point one

student to as phyllis who's studying business

and she has a three point

e.

so

what we can actually do is we can

use functions inside of these class files so I can actually define a function

instead of this student class and then all of my

student objects could access it.

so for example,

I can come down here and create a function and

let's say we wanted to create a function

that

told us whether or not this particular student

had honours

so whether or not they were on the honor roll right

basically like,

are they like a really good student

so I can define a function

call

on

honor roll

and

basically what it's going to do,

it's going to tell me whether or not this particular student is on

the honourable

and

let's basically just say the rules are being on honor roll is you have to have a

gps iif

three point five or above.

so here gps three point five or above that means you're on the honor roll

well

over here I could actually

write the code for that so I could say

if

self dot gps.

and when I say self over here

this is referring to like

the actual students gps

and you'll

notice over here I have to pass that in

as a parameter.

and that always has to be the first parameter so I could say if

self dot j e p a

is greater than or

equal to

the read point five.

then we can return

true

because this student

is on the honor roll

otherwise

an else

we can just return

false because

if their gps

isn't above a three point five that

they're not on

the honor roll.

so

that's essentially our little on honorable function and you can see it's a very small function,

but it provides

a service to the objects of this class right

it allows

the objects of this class to

figure out whether or not that current student is on the honor roll so

over in this app dot pi file.

I could just print

out that values so I could say

print

and I'm gonna see if

student one

is on the honor roll.

so

now when I run this you'll see it should print out false

and is putting out false

down here

because student one only has a gps

of

three point one.

if I was to do the same thing on student to

students who has a gdp of three point

eight

so we should return true.

and that's exactly what happens so

essentially a

class function is just a little function that can be used by the objects of the class and I would say this is a pretty good example of

what a class function should be doing

should be like giving us information about the class or it could also be like modifying information about the class.

and so that's the basics of using functions and classes I mean this is a pretty simple tutorial but

I really just wanted to introduce you guys to the concept

of

pudding

met functions

inside of classes this is going to be really useful and

if you're making a class you always wanna think about like what functions can I put inside of here

that will

you know essentially

healthy user to either figure out information about the object

or

modify different values in the objects

in this tutorial on antarctic guys about inheritance

in

python.

inheritance is basically where we can define a bunch of attributes and functions

and things inside of a class,

and then we can create another class and we can inherit all of those

attributes.

so I could basically

have one class that has

all the functionality of another class

without having to physically write out any of the same

methods or attributes.

so it that's confusing don't worry I'm

sure you guys exactly what this is

in this video so

let me show you about some stop I have set up over here.

I created this class

called

chef

and over here we just have this class chef.

and inside of this chef class we have three functions

so the shaft can do three things.

the chef can

make

chicken.

the chef can

make solid

and the chef can make

a special dish.

and whatever the chef makes a dish

he basically just says

the chef makes a chick in order the chef makes

a salad

or the chef makes barbecue ribs for this special dish.

so basically just

saying whatever the chef is doing so

if I was to come over here to my app dot python file,

you'll notice that I'm importing the

chef

so I'm basically

allowed to use this chef class now,

and I can say

my chef is equal to shafts I'm creating a new chef.

so now if I came down here and I send my

chef

dot

make

chicken,

when I run my program.

now it's going to say,

the chef makes a chicken.

if I said

make

special dish

and are on the program.

now it's going to say the chef makes barbecue ribs so it because that's the chef's

special dish.

so I have this really awesome chef class and it works really well.

but let's say that I wanted to create another class

to model another type of chef

rise to this

chef class is just modelling like some generic schafroff

we're representing some generic chef

in our program,

but let's say that I wanted to create

a

class that modeled the different type of chef

for example,

let's say we wanted to create a class that modeled a chinese chef.

so instead of just a normal chef this is a

chinese chef,

well I actually created a file over here called

chinese chef dot python.

so we can actually use this

chinese shaft out python file to create our chinese

chef

class

tom's going as a class.

and over here I'm just going to say

chinese chef

and

basically

I just can define everything that the chinese chef can do,

but let's say that

our chinese chef

can do

everything that are generic chef can do.

so the chinese chef is like a special

schafroff it's very specific type of chef.

but let's say that this chinese chef

can do everything that the normal chef can do so the chinese chef can make chicken

can make salad,

and can also make

a special dish.

well if I wanted to give this

chinese chef,

all of that functionality.

I could just come over here and I could copy all of these

functions.

and I can paste them in here

and so now the chinese chef can do everything

that the other chefs can do,

but let's say that in addition to all of these things the chinese chef

can also make

a special dish called fried rice

so I could say

deaf

and we could say make

fried rice.

so

the chinese chef has this extra

function which allows it to make fried rice.

and over here we just say,

the chef makes

fried rice.

and let's also say that

the chinese chef has a different special dish so instead of making barbecue ribs.

the chinese chef makes

lunge

chicken.

all right so now we have our chinese chef class set up

and you'll notice that it can do everything

that

the normal chef could do.

so let's go back over to our app dot python file and I want to create

a

chinese chef

object.

so

instead of importing from chef

we're going to just import it from chinese chef.

so I'll say

chinese chef

and we're going to employ for

chinese chef.

so let's go ahead and make

a chinese chef

object

sit down here I'm going to make one arrow to say

my.

and then

my chinese chef.

we can print out this special dish so

remember the chinese chef can do

everything that the normal chef could do

so if I say my chinese chef da

make special dish.

when I run this program you'll see

the

regular chef is making barbecue ribs and the chinese chef is making orange

chicken

so everything works out.

and this chinese chef also has an extra method called make

fried rice.

and

you can also

make

fried rice.

but here's the problem right when I go over here to this

chinese chef dot pie.

I went I wanted to use all of the functionality that was inside this

chuffed class

I actually had to copy and physically paste.

all of these functions down

into this file right

and that's kind of a drag.

and they especially like imagine if this chef had like

twenty or thirty of these different functions in it.

we have to copy and I have the pace.

all of those inside of this chinese chef

and this is where we can use something called inheritance

so instead of having to copy and paste

all of these functions.

I could just inherit these functions

from that

chef class

and in order to do that,

I can actually just get rid of all of these,

and I can come over here

and

right next to where I'm saying class chinese chef

inside of the parentheses I can say the name of the class that I want to inherit from so I can just say a chef.

and I'm also going to have to import this song to come over here and we'll say

from

chef

in poor

shelf.

so basically what this is saying is

inside of this chinese chef.

I want to be able to use all of the functions that are contained

inside of the chef class

so say that one more time

inside of this chinese chef class

I want to be able to use all of the functions that are inside of this

chef class

so

by using inheritance here

I'm actually able to come over here to this anecdote pi file.

and now

I'm still able to execute for example like

the make

chicken

function.

even though I didn't specify the make chicken function in here I didn't write it out.

I can still run this program

and the chinese stuff.

the chinese chef will still be able to make

chicken.

so when I run this program

you'll see it out here it says

the chef makes chicken

and that's because I inherited the make chicken method

from

the chef class

but here's one thing

that

got my stuff

if I come over here and I say make

special dish.

remember the chinese chef

special dish was supposed to be orange chicken.

but now

the chinese chef is going to be making barbecue ribs

because

I inherited

this makes special dish

function

from this

chef class

is what I can actually do is I could come in here and I could

override

that

make special dishcloth

so I could say

death

make

special dish.

and down here

I can just

override it so I could say,

the chef

makes

orange

chicken

and now

when I go over here and I run

this

make special dish

function.

now the chefs are going to be

back to making orange chicken so the chinese chef will make his

special dish.

so that's

basically what inheritance does it allows me to inherit

functionality from an existing class into the new class.

and

I can actually just inherit all of it without having to write it out so I didn't have to write out

make

chicken and make solid inside the chinese class,

but

the chinese chef

can still make

chicken and salad because it inherited that functionality from the chef class

in this tutorial I wanna talk to you guys about the

python interpreter.

the python interpreter is basically a little environment that we can use to execute python

commands.

so it's kind of like this little sandbox environment where we can test out and try out different

python commands are different python functions

in a very safe and neutral environment.

so it's kind of like a quick and dirty way to write python and try different things out.

the way we use the python interpreter is by opening up

opening up our command prompt.

now if you're on windows there's a program called command prompt

if you're on mac there's a program called

terminal.

basically you need to open

that program in order to use the python interpreter,

so I'm here on a mac

but if you're on a window as you can

essentially do exactly what I'm doing just

inside of the command prompt.

so on mac here I'm just going to search for

my terminal.

if you're on windows you can just search for like cmd or command prompt in it should pop up,

so the terminal is

basically an environment

on our computer where we can

interact with the computer and do different things

without a graphical user interface so normally when we interact with the computer

we're using things like buttons or you know windows and you know what we can move stuff around we can

you know basically just like

interact with the computer.

with graphics

with the terminal or the command prompt

is a place where you can interact with the computer using text commands.

so you know am I going to get too much into

what the terminal the command prompt dog but that's essentially what it is.

so inside of here,

we can use the python interpreter

and the python interpreter is basically just a little program

that like I said and we can write

you know sort of python

in

so generally,

all you have to do is go over to your terminal or your command prompt

and type in

python

three

and since we're using python three on monotype python three.

but you can also just like normal python and I'm pretty sure that gives you python two.

now here's a quick disclaimer.

I'm

on windows,

you may run into a problem

where

you can't use this python three command,

and it's possible that

if you're running into that problem

python

python three hasn't been added to your windows

path variable.

and basically what that means is your computer doesn't recognize the command

python three

and that's the case

all you have to do is just go and google

how to add python three to your windows path variable.

it's really easy I'm not going to get into it in this video just because it's kind of

outside the scope

but

if you're running into that problem.

that's probably it's not on your windows

path variables such as google around for that and you should be able to find an answer,

but onsite python three and then click enter

and it's going to open up this cool thing down here so

you can see it basically just says like here's the version of python.

now

I'm

going to enter so we can have some like

new lines here

and

put down here this is the python interpreter so we can write

python code in here and it's going to work so I could

for example I could write like

print

and inside of here I could print like

hello world.

and

when I click enter

you'll see that it prints out

hello world.

I could create a variable so for example I can say like number one

is equal to ten.

I can say numb two is equal to ninety.

and then I could print

out number one

plus

none too

and it's going to be able to do that for me ?

I could also use awesome like a function so I can define a function in here,

we can make a function that is called say hi and it'll take a name parameter.

and

you'll see here when it saw I wanted to create a functional

put these three little dots

and I can index in and we can write the code for a function so I can say like

print

hello

last name.

and now I have a function called

say hi so I can break out of this by this entering again

and I would call the function so I could

say

say

hi

and we'll say out of me.

I'm like

so now it's going to say

hello mike

so I can use a function I could use something like an

if statement

you know

I could say,

I can easily afford the wicked use while loose.

I mean we can basically use all of the basic like python commands and you know

inside of this python interpreter and like I said before.

it's essentially just an environment where you can test

out

python code.

now this is not a place where you want to write

like any serious python

scripts

so if you're like designing and writing a python program

I would not recommend

doing it inside of this interpreter ?

it is,

it's not a very intuitive environment it's pretty much just set up for some quick and dirty tests

we need to test somethin' out great this is a perfect place for it.

you'll have to set up a file

you'll have to use like some

id you don't have to execute a filing is going here it's quick it's dirty,

you get it done.

but if you're writing an actual program.

you definitely definitely definitely want to use

a

text editor.

the text editor is just going to be way more organized everything is going to be a lot cleaner and you're not going to get confused with like where stuff is and what you have so

that's the basics of the python interpreter,

you know in the course I

havent really been using it at all,

just because I think it's a lot easier to teach when we're inside of a file,

then inside of here but

you know

don't count this guy out

the python interpreter is awesome a lot of people who use it and it's great if you just need a task

you know little bits of code out without having to set up some

huge environment so

python interpreter

definitely awesome out player out there you know have some fun

and take advantage of it.

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