Original subtitles

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So it's a tradition, when learning any new programming language,

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that the first program you write should print out the text Hello World,

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and we're going to do just that in this video.

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So start Intellij DEA, as I have, and choose Create New Project from the Main menu.

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Now if you're using a different IDE or editor, use its command for creating a new Python project.

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So we want to select Python, on the left hand side, as I've done here,

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and also make sure you've got a valid Python SDK selected at the top right, and click on Next.

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Once you get to this screen, you can type in the project name.

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So I'm just going type in there, Hello World.

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Now I don't like using spaces in the names of things, as that can cause problems.

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To make the name more readable, I've used Pascal case.

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I've used a capital H for the word Hello, and W for the word World.

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Now you can change the location if you want, but make sure you don't put one project inside another project directory

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So what I'm going to do, and I'll fix up that spelling first,

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I'm going to move to a new folder, just to show you what you would do, the first time you're setting this up.

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Then come to the folder.

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That's my main folder where I've got all my different programming languages.

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I'm going to create a new project.

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I need folder, rather, and I'm going to call

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this one python-masterclass-remaster-shared, and this is just a format that I've used on my computer.

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Alright, so scrolling up here, i'm gonna do the same thing that I've done for my java masterclass.

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I'm gonna create a subfolder called current Java masterclass remaster, but we're going to obviously call that Python.

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And this is just the way that I've set things up:

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python-masterclass-remaster, and I think I called it current at the start, so I'll put that current,

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and that's where all my projects are going to go, in that folder.

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Now the first time you do that, you create a new folder. If we look at the end of this project location,

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note that it hasn't got the project name there.

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So what you'll need to do for the very first project, is put a slash in there, and HelloWorld, being the name of the project.

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Subsequent times that you create new projects, it'll automatically find this project location,

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and put the project name after it.

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Alright, so at this point now that I've done that, I'm going to click on Finish.

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You're prompted now, do we want to create that folder?

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This is, I know it's a long path, but this is the path that I'm storing my files on a network drive, so for me that's valid.

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You would choose whichever folder you wanted to, and make sure that was valid and then click OK.

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At this point, IntelliJ is setting up the project.

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Now it won't take long but it's a good idea not to do anything until it's finished.

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So you can see the messages down there in the status bar, at the bottom of the screen.

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Wait for these to disappear, and you'll see IntelliJ uploading skeletons, whatever that means, and indexing the project,

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and then the project's been built and we should see the project pane open, and we'll be able to see some files there.

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Alright, so you can see now the project pane open. There's no more,

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well actually there is a bit, there's the updating skeletons message you can see down the bottom there.

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So we'll just give that a moment to finish.

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Once it's done that, we can get started.

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Alright, so you can see now it's finally finished. There's now no more working messages appearing in the status bar.

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So what we want to do is create a new file for our program.

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So you want to make sure the project pane is open and you can see it is there.

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If it wasn't, by the way, you can come over here and click on project,

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and that will open and close the project tab. So make sure that's open.

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So at the top of the project pane in bold, is the name of our project.

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That's Hello World in this case.

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So make sure that you click on this, which I'm doing now,

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before we do the next step, and once we do that the file menu changes, depending on what you've got selected.

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So after clicking on the Hello World project, which I've just done,

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I can either right click and select New, Python File.

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Alternatively, I could come up here after selecting that and click on File, New, Python File.

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Either way will do the same thing. Okay, I'm going to call this one helloworld.

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Then note that I've typed it all in lowercase with no spaces.

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IntelliJ will automatically add the dot py extension to the file, which is what Python files typically have as their source file,

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but if your IDE or editor doesn't do that, then you would type in the full name, helloworld.py

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I'm gonna click on OK

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and we can see there in the project pane to the left, that it has been named with helloworld.py.

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So at this point we've now got a new Python file open in the editor.

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I'll talk a bit more about these files and directories in the project pane later.

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The best advice I can give at the moment, is that if you didn't create a file or a directory, then don't mess with it.

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You'll get strange problems if you try and put anything in that .idea directory, for example.

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The only thing we're interested in at the moment, are the .py files that we create,

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and obviously helloworld.py is the one that we've created for this project.

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And for the moment they should all be created inside, directly inside, the HelloWorld project structure,

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and that's what we've done here.

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Alright, so in terms of the actual code for our first program, it's extremely simple.

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We're going to come up and start typing print left parenthesis, noting that a right one gets added for us automatically,

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single quote, noting that a second single quote gets added automatically,

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and if you're using another IDE or editor, you'll need to perhaps enter those manually yourself.

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We're going to type Hello, World and an exclamation mark,

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and that's literally it. That's our first Python program.

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To run the program, we want to right click anywhere here in the editor window, which is where we've typed our code,

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right click and click on Run Helloworld.

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You can see straight away, the output appears in the run window at the bottom,

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and that's initially configured to be at the bottom of the screen,

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and we can see the output, Hello World!

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And that's our first Python program.

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Although it's very simple, our Hello World program does include a few important basics.

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Firstly, we've used the Python function print.

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Python has many functions,

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such as mathematical functions like round, to round the number of digits after the decimal point

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and char, chr and ord, to convert characters to their numeric representations and vice-versa,

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as well as many more.

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You can also define your own functions, as we'll see later.

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In the next video, we'll see more ways to use the print function.

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See you in the next video.