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In order to finalize our understanding of functions, we have to talk about scope, another one of our

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key terms.

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What is scope?

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Scope is something present in a lot of programming languages and scope simply means what variables do

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I have access to?

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So what do I mean by that?

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Well, we've seen this before, right, where I do print and then let's say, Nate, if I click run.

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I'll get an air, a name, air name, name is not defined because, well, it doesn't exist, right?

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And up to this point, we haven't really discussed this, but this is because of scope.

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What variables do I have access to the Python interpreter says, hey, what do I have access to?

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And when we use something that it doesn't understand or doesn't have access to, it's going to throw

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a nightmare.

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Or variable is not defined, air and scope in Python has what we call functional scope or function scope.

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What does that mean?

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Well, up until now, when we create a variable like total equals to a hundred, this is part of what

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we call global scope.

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That means anybody on this file has access to this total variable.

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I can use this inside of a conditional block.

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I can use it inside of a function.

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It has global scope.

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But when I say Python has function scope.

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What I mean is that when we create a function and let's say we create total as some or let's say some

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func.

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And we create total inside of the function, if I print total here and I click run.

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I get the same thing, name total is not defined, this is because of Python's function scope, any

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time we create a variable, if it's not inside of a function.

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Then it is part of the global scope, we have access to it, but you see over here we get that red underlined,

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undefined name total.

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If let's say, for example, I had a condition if true.

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Then X equals to 10 if I do this and I say X and I click run.

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I have 10 because, well, although I have indentation.

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The only time I create a new scope, you can think of this as a new universe that we spawn.

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Well, we can only do that when we define a function like this, so think of scope as a new world that

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we create in our case, when we create a function, we create a new world that anything that's indented

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inside of the function is its own world that we don't really have access to.

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We can only use total if we indent print.

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And it's part of this world.

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That's what scope is, who has access to who.

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So let's take a break here and I want to play a little game in the next video where we try and figure

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out who has access to who.

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I'll see in that one by.