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I want to address a question that you may or may not have, but it's something that's taken me years

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to understand, and that is why not just have everything as global variables?

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I mean, all this confusion of who has access to who, how easy would it be if everything was just on

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the main page, all our information, all the data on our global scope so that everything has access

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to everything.

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Wouldn't that be easier?

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And you'd be kind of right.

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I mean, that would make all this headache go away, right?

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But you have to remember that machines don't have infinite power, don't have infinite CPU, don't have

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infinite memory, they all have limited resources.

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And as programmers, we have to be conscious of what resources we use because sometimes that can cost

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us money, sometimes that can crash our computers.

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And scope is a great demonstration of this.

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For example, this code right here, when this function is run, we're creating technically just one

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location in memory for the X variable.

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So we have that bookshelf in our computer that is X that's pointing to local when we actually call this

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function.

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And then when we say nonlocal here, well, we're saying just don't create another bookshelf for us.

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Just use the one that we already have and assign it nonlocal.

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If we didn't have this line, by the time we get to line seven, we've placed in memory X equals to

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local and X equals to nonlocal.

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So we have two locations now in memory.

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Now, this isn't a big deal because, well, in this day and age, we do have a lot of memory.

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But as programs get larger and larger, this does become a bit of a problem.

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OK, but what about a function?

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I mean, we learned that functions allow us to not repeat ourselves and being able to call out are multiple

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times.

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But another good use of functions is that once we called this function and all of this is done, the

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computer and the Python interpreter specifically destroys all this memory.

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That is, once we finish with the outer function, I can't really call print X here.

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It's going to give me an error.

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It's going to say I have no idea what exists.

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And why is that?

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It's because after we call this function, the python will be called the garbage collector is going

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to say, hey, it looks like we're done with this function.

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And I see that this X variable well, and this X variable we're not going to use because we're done

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with this function.

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So I'm going to collect that garbage and then just throw it out.

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So I'm going to empty that memory cupboard so that other resources or other programs can use that.

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And that is a really nice feature where Python just automatically removes these for you so that you

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don't clog up the computer's memory.

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And that's why SCOP is useful.

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We don't have to think about it in such detail like I've mentioned it, but it's nice to know that it's

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there so that your programs don't hog up a lot of memory and they can run efficiently.

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This is a bit of an advanced topic, but I did want to include it in here so that you can think about

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why programs are designed the way they are.

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All right.

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I'm going to stop talking now.

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I'll see you in the next video.

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Bye bye.