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Oh yes and welcome back to another class of our course about the complete introduction to fight on programming.

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So today we are going to still talk about lists but instead of just talking about the basics we are

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going to talk about list functions.

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So as we said the beginning of this squares there are many types of functions that exist.

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You can apply function to strings you can apply functions to numbers you can apply functions to well

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you have many types of functions on Python but you can also apply functions on lists.

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So what exactly are list functions.

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So technically it's just simple manipulations that you can do on lists by yeah.

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Well writing down functions so functions can for example.

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I don't know help you add something in your list can help you let's say copy and past your list can

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help you count the number of elements that you have in your list.

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So what I personally done you have you have hundreds of different functions but what I personally have

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done I simply look for the most popular functions that exists about the lists and I selected five of

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the most used functions for lists.

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Well the most use that list functions that are used in Python.

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So basically what we will do today is I will show you I'll give you an introduction to functions to

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list functions.

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And if you guys are interested you can after that go on the internet and just find out many other list

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functions and try them out by yourself.

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So we'll see it's not very hard to understand.

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All right.

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So let's start the first thing that we are going to talk about will be the function answer.

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So let's say for example the first thing they'll ask you is write down a book well two lists so a list

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of numbers and a list of a list of strings.

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So we'll start by the first function.

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This function will help us insert something in a list.

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So let's say for example in this list of words where this is this list is called food and I want to

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insert another type of food right here.

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So what exactly I will do.

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So let's say for example I want.

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Well I'll start by printing this list.

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I want to print my list that is food.

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All right.

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So if I print my list I will receive this this answer.

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So Hamburger is a juice price let's say for example I want to insert something in my list since lists

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can have millions of different elements.

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And I'm interested right now to insert one element in this list.

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So to be able to do this what I will do I will use the insert function.

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So how this function works.

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Very simple.

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You write down the name of your list dot insert.

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Then you will add the index in which you want to insert your your your element.

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So let's say for example I am I want to insert another word right here.

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So right here will be the element number 2 so 0 1 and 2.

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So this will become the element number two.

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So the index well the object or the element.

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So let's say I am writing so I'm gonna write down the index number two and then I want to insert let's

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say in this case I'm interested to insert spaghetti for example.

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So spas getting great.

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So what I just did is I insert the in the index number to the words spaghetti and if I run my function

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if I run my up as you can see I will have hamburger pizza and spaghetti right here and not forget one

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thing in Python we always start counting by 0 0 0 1 2 3 4.

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So this will become the segment element that we have or the second object.

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All right.

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So this is the first type of function.

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This is the first function we'll talk about the second one will be very simple.

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It's simply delete delete.

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So let's say you want to delete all your list.

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So this list you want to delete it for example.

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So what you can do is simply delete everything manually or just write down delete right down the delete

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function.

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In this case how it will look like.

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So let's say for example you write down your food and the word says it it's going to be the clear function.

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So very simple.

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You write down clear you open and close the parenthesis.

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So what we ask Python so as you can see right here we ask Python to clear our func to clear our to clear

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our list food.

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So here we have our list and we ask Python to clear it.

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So when we run the app as you can see we have nothing in our list.

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The same thing as if we have deleted everything.

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All right.

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So right now you know how to add things in your list and how to delete things in your list.

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Right now let's say you want to put a list into another list.

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I'll just take this out.

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So let's say you want to integrate the prices into the foods.

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So in this case what will happen.

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You want to put those two lists together.

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So let's say for example you have one list of food and you have another list of food and you want to

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put them all together in one simple list.

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So what we'll use as a function to be able to do this there is a function called extend.

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So you will simply extend your initial list and add more elements at once so you can add another list

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to your first list you can add variables to your list.

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So how exactly this works.

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Very simple.

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So we start with our first list which is food.

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So write down food we click on that then the function as I said will be extended so that it will be

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this one and what you will write down inside your parentheses will be the second list that you want

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to add.

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So in this case we want to add the price the prices.

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So right now we have our food that extend and the same list.

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So if we run our app as you can see the food the food the list the list food became the list food and

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the list prices.

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So this is a way that you guys can put two lists together simply by using the extend function.

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So this is another way that you can.

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This is another function that you guys can use to be able to work with lists that you can see it's not

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something that is hard to work with.

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But once again those are some manipulations that you guys can do with your lists.

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All right.

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Let's say right now that you guys are interested to find.

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Let's say what what is the index of a certain certain type of food right here.

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So let's say for example you guys are looking for pizza because here it's simple.

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We only have five plus one six elements.

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But let's say you have hundreds of elements and you're interested to find one of those.

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So it's like in Excel you or you will lose them.

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You will use the view lookup function in Python.

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What we have we have the index function.

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So in this case what you guys will do is very simple.

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So we will use our print function and let's say we are looking for pizza.

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So what exactly we write down we'll write down our print and what exactly we are asking Python to do.

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We will take our list and that from this list will simply write down index.

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Our function will be index.

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And from here we'll write down the element that we are looking for.

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So we are looking for pizza.

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We write it down and then we simply run our function.

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So as you can see pizza is the first element right here.

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So we have zero then we have one.

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If we write down another element which in this case will be juice normally we should receive no for

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why no sorry.

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Why.

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Because we have a hamburger as number zero pizza as number one juice as number three and spaghetti as

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number two which makes sense because we put it spaghetti right here all right.

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Next function that we are going to talk about will be the challenge function.

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Let me just show you how it works.

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Let's say for example you have one type but what you have right here is the only ones.

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But let's say you have pizza five times so what you guys will do simply take the pizza and you can copy

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and paste it let's say at the end of the list twice.

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All right.

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And that will do the same thing for Jews as well so we'll try it multiple times so you guys will understand

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how this function works.

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All right great.

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So right now what we want to do we want to print the number what we want to count the number of times

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each of those words is repeated.

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So what we will do we'll do this for all the words.

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So in this case we have hamburger as well so we just copy and paste it

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and we have sushi great.

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So yes I have copied and pasted everything.

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So what we will do will use a function that is called the count function.

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In this case how it's written very simple once and we'll write down our friend function right here and

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we will ask Python to go in our list and to count how many times this element is repeated.

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So in this case let's say we want to know how many times pizza is repeated and we run our up as you

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can see pizza is repeated three times if we want to do the same thing for Jews we can do it

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we run our app and as you can see Juice is repeated three times if we do the exact same thing for sushi

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is

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as you can see it's run two times.

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Not forget the eyes it's very important that you write the exact same word right here.

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So let's say for example I start to shoot up the letters as you can see it's zero because I don't have

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sushi with capital letters right here.

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So very important you need to write down the exact the exact word.

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If not it's just not gonna work.

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All right.

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Let's thing we are going to talk about today will be copying lists in this case what we guys.

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What you guys want to do let's say for example you want to copy one of those lists.

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So it's very simple how this works.

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Let's say you want to create another list.

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So we'll name it

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let's let's name it random random and random will be equal to our food copy.

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So in this case food copy so very important you open and close parentheses.

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So it will be the copy of the list food.

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So in this case we want to have the copy of food.

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So we simply write down food that copy.

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In this case while it will copy food plus prices that copy.

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So what I just did I asked by Don to create another list that will be random that includes the list

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of food copy and price copy.

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And in this case if I run my app just a print

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say I want to print everything.

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So in this case I'll print random right.

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All right.

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So as you can see I have my list right here all my lists.

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So I have my first list and I have my second list.

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Once again it's another way to well to create a list.

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So right now I just copied the food and I copied prices so as you can see guys.

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Those are the basic manipulations that you can do with lists.

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Those are some basic functions that exist.

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You have many many others.

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If you guys are interested to learn more about list functions once again I suggest you to simply go

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on Internet and type list functions.

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You'll have hundreds of them that will appear same thing format functions in some.

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Same thing for a string of functions.

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But my goal right now is really to show you what exactly are those functions and how they work.

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So right now you understand all this and you can go to the next step of our course.

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That's it for this class guys.

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And see all in our next class.