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Welcome back, everyone, in this lecture, we're going to discuss while loops.

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Now, while loops are loops that are going to continue executing a block of code, while some condition

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remains true, unlike for loops that end up iterating through a sequence in order to execute blocks

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of code while loops keep going.

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So for example, while my pool is not full, keep filling my pool of water and then stop the loop when

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the pool is full.

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And we can do it with just a simple line of code saying while, for example, while my dogs are still

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hungry, keep feeding my dogs.

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So this means in the syntax of a wire loop, we're actually checking while some bullying condition is

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doing something, execute a block of code, you can almost think of this more like an if statement that

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just keeps going over and over and over again for that condition until that condition is false.

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In fact, let's go ahead and jump to our code editor and check this out.

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OK, so here I am back at the coding editor.

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But I'm going to first start off with is assigning some variable end to a number like one.

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And then what I'm going to do is set up my while.

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So I say while and then I have to figure out some sort of condition.

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Now you always want to be careful for a while, loop not to do something like while true colon.

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Prints some letters here, because this is going to basically execute forever.

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It's going to be while this is true, always run this block of code.

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So you really want to be careful of something like this because that essentially says, run this forever,

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never break out of this wild loop.

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So instead, we want conditions that are probably going to be affected either by some outside source

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that we're checking or internally within the block of code inside the wire loop.

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So going say something like while M is less than five, I'm going to print out the current value events

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I'm going to print out and is currently.

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And then let's use a string literal printing here.

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So I'm going to say, while an is less than five print F and is currently RN.

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And then if I just run this by itself, there's no change to an ever.

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So this is going to print out forever.

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Hey, and it's currently one and is currently one and is currently one.

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I want to avoid that.

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Otherwise I'd have to somehow figure out how to kill the Python kernel.

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Instead, I want to make sure I can update the current value of.

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So then I'm going to say NW is equal to and.

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Plus one.

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And so now let's think about what's happening as this keeps looping.

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So it's going to start off with an equal to one.

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It's going to report back and is equal to currently one.

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And then it's going to reassign men to be equal to the current value of N plus one, which is then going

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to be one plus one.

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So it's going to be two.

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There's going to run this again and it's going to be three, then it's to be four.

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And then suddenly, once it hits five five, it's no longer less than five and the while Loop will stop

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executing.

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So you should see the results look something like this and is currently one two three four and then

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it stops executing.

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So while loops can be really useful when you have the ability to check something that's happening outside

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the wire loop, we could do something like Prince Hey, Server is up.

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And then in the while loop, I could have some other function.

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Let's say somewhere else in some other piece of code that could be something like check server.

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And then I would have here something like, let's say, server condition or a server up.

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And then I would have this be something like, OK, have the check server report back whether or not

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my server is up true or false?

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And then I can print out, OK, the servers up continually until it's not up.

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So that's the kind of thing I could do if a while loop again, we haven't really learned about functions

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yet.

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We're about to learn that next.

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I just want you to give you some ideas of how this could be useful.

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It's when you want something to continually go over and over and over again in a loop until some condition

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is no longer true.

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Again, it's while some condition is true.

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Keep doing something.

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All right.

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So that's it for the wire loop.

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Coming up next, we're going to discuss functions.