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Welcome back.

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Let's keep going with some more stirring methods.

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Now we've learned about adding and removing once we learned about a penned insert an extent and then

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a removing we learned about pop remove and clear there's a few other important ones.

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Let's go with the index so instead of clearing here let's clean this up and we'll do basket dot index

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and index as you can see we give it a value a start and a stop.

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What does that mean.

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Well we want to say hey what index is number two if we do index of two and I click run it's going to

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give me one.

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I know this is a little confusing but it's asking for the index Where is number two.

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Number two is that index of 1.

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Let's change these into letters just so it's more clear.

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So we have a b c d.

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And then finally e and again if I do D here and I click Run I get an index of 3 because 0 1 2 3.

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It's on shelf 3 in our memory.

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And you can also do a optional parameter here which is where shall we start looking.

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So I want you to start looking at index of 0 and then finish looking at index of 2.

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If I do run here I get an error.

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It says hey D is not in List because while we started at index of 0 and stopped it index of 2 if I do

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three and I click Run No it stops right before three.

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So if I do four and I click Run there yo I get three now errors are not good or in our programs ideally

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we don't want to get errors.

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So how do we avoid this.

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What if we're looking for something and we're not sure if it's in the list or not.

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There's another nifty way of looking for things in that list and this involves what we call a python

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key word a key word is something that you use in Python that well already has some meaning.

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For example a keyword here if I go to Python keywords are all these wars that already mean something.

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Now we're gonna go through them and we haven't seen a lot of them yet but you might have seen true right

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in boolean values to mean something.

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So in Python we can't really use the word true because well it already means something.

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There is a word called in that as you can see as soon as we type means something as a keyword in Python.

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And this is quite nice.

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We can say hey is D in the basket and if I run this I get true okay is X in basket I get false because

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well it doesn't exist and this is actually quite useful and we can even do it for strings for example

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if I'm looking for let's say the letter I in a word and let's say it's I in.

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Hi my name is Ian if I click Run I get true because the letter I does exist in this string.

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All right well let's learn another one Another one is basket dot count and we can count how many times

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an item occurs.

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So for example if I do D and I click Run I get one because D only exists once in the list but if I add

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another D in here and I click Run we get to it counts how many time this value occurs in our list very

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very useful.

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All right.

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A few more still to go.

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Let's do some exercises and I'll see you in the next one.