Original subtitles

0 So you learn that a for loop iterate through a container which could be a list, or a string, or a tuple. 1

And the loop will terminate when the container is exhausted. 2

So for example it prints out one, two, and three. And when there are no more items 3

the loop ends. 4

So a full loop runs until a container is exhausted and a while loop a while loop runs as long as this 5

condition is true. 6

Let me execute that and see what is going to happen. 7

So you will see that 1 is being printed out all the time. 8

So if I scroll up here I will not be able to find where the starting point was because there's a million 9

ones now being printed out there every split of a second. 10

So what's going on here is that a while loop, while is a keyword, and then that is followed by a condition. 11

In this case the condition is that A is greater than zero which is true. 12

So A is actually 3. 13

That means this condition is true. 14

And as long as this condition is true, this will be printed out, so under the while loop you can have 15

as many actions operations as you want. 16

For example let me interrupt this with control C on your terminal. 17

And then add another line here print2, save, execute. 18

So 1 2, 1 2, 1 2, 1 2, 1 2 19

is being printed out. 20

Okay I'll interrupt that. 21

Not the rate that these numbers are being printed out 22

depends on your computer. 23

Processor speed. 24

So the faster your processor, the faster you will get these action here, 25

these operations being executed. 26

Now of course this will always forever be true because it's a just a static declaration of a variable 27

here. 28

So no one is changing it here, therefore of a condition will always be true. 29

You can see inside Python when you check something like 3 is greater than 0 you get true. 30

So this is basically while True, and you will sometimes see it like that. 31

So just delete the first line. 32

Exit here, execute the code again. 33

So again the same thing happens because true is always true. 34

However, this is not how while loops are used in real world. 35

It's meaningless to check if true is true and print out something all the time. 36

So let me go ahead and explain while loops in a better example in the next video.