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Instructor: Welcome back.

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When we talked about lists, we saw our special type of None

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where some methods that worked on lists

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didn't really produce anything.

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They modified the lists in place,

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but the output of whatever they were doing,

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was this thing None.

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Remember how we had in the output, this None?

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What does that mean?

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If you remember,

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I mentioned None as a special data type

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that exists in Python

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and most languages have something like this

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to represent the absence of value.

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In some other languages you might have heard of Null

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which is another thing that, again,

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represents the absence of value.

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Now, why is this useful?

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Well, for now it's hard to really conceptualize it.

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We'll see it being used a lot more

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as we get further into the course,

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but I could do something like a = None.

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Let's say for example, we're just starting a video game

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and in this video game, we have a user's weapons.

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But when you're just starting the game

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there are no weapons that the user has.

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Well, in that case,

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we might wanna assign the variable weapons.

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Maybe in our code we use this variable,

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but we also wanna know

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that this user doesn't really have any weapons,

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it's None.

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So this is completely valid Python.

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If I run this, I get None.

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And we'll explore this a little bit more

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throughout the course,

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like I said, but hopefully this way you're not

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intimidated when you see it, as the name suggests,

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it's just nothing.