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Hello guys and welcome back to another class of our course about Python.

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So until now we saw many many things and we talked about the if statement.

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And right now it's time to put everything in practice.

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So what I want to do in this class is really practicing the if statement that we learned before it as

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well as the functions and the putting everything together so very simple.

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What I propose you guys doing today is a small basic app that will be a conversation between a user

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and a person.

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So in this case what exactly will the app look like.

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So the first thing we will do is we'll tell the rules to our users.

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So the rules will simply be answering each question by yes or no.

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So if the user says yes to this I will go to the next question.

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If the user says no we'll simply print stop then ask the first question the same question.

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The third question and the fourth question.

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Well the third question because it stops at trick questions.

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So basically this is the goal of our app.

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So let's start.

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So very basically.

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But what exactly will start in this case will put everything inside of a phone it of a function.

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Because if we don't do this it simply will not work.

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All right.

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So how exactly this will work.

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Well write down firstly def so def is a way to tape them to tell Python that we start our function here.

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The name of our function will be question.

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So simply name the question.

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You write down two points.

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All right.

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So first thing we'll write down rules.

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So the first variable that we will have inside of our of our function will be the variable rules.

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In this case we'll ask our user.

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You need to answer every question.

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So we'll write it down.

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You need to answer

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every question by yes or no.

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Do you under stand.

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So you're our user will give us an answer by yes or no.

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All right.

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So once the user read this he will answer.

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So we'll start with our if statement.

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So if the variable rules is not equal to yes.

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So if it's equal to no.

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So if the variable rules is equal to no we want to return stop.

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So in this case we'll ask Python to print stuff or will print and we'll ask him to print trade.

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So let's say try again

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great.

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So you can see yes right now our first rule is very simple.

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If we if our user returns.

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Yes we go to the next question.

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If no the the apple stop here.

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Well our function will stop here.

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This is why we use the return statement in this case will stop our function right here.

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If in the case that this is not respected great.

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So once this is done it's time to write our second question.

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In this case it will be else.

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So what's happening in the case that this is not respected.

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Well this is respected.

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So we'll print next question

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great

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so we have everything right now.

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Next thing that we want to do is write down the first question.

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So once again we'll use a variable to write down the questions or in this case we'll have question 1.

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So quest 1

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and the question 1 will be very simple.

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We'll ask our user.

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Are you hungry.

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So once again we'll write down an input because we want an answer from him.

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Are you hungry

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and once again we'll have our if statement.

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So if the variable quest one

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is not equal to yes or is equal to no.

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We want to return.

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So we will give the answer to our user.

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Then let's go for a walk.

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In this case

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we'll tell this to our user

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so once again the question is if this variable right here is not equal to yes we want to return to our

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user.

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Then let's go for a walk and everything stops here.

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So the app will stop there.

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In the case that the answer is yes.

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So here is not yes.

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If the answer is no we return this in the case that the answer is yes.

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What we want to do well we simply go to the next question.

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So we print else.

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Next question.

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So what's the next thing.

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So right now we'll ask our user.

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Do you want to eat at a restaurant.

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Since our user is hungry we want to ask him if he wants to eat somewhere.

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So once again we'll store our variable right here So write down our input function and ask our user.

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Do you want to eat at the race.

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Great.

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So right now we have our second variable or our second question.

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Now it's time to ask the equity question so we'll write down the function if the if statements are.

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So ask our user if we'll tell our user if the answer to the question number two or the value of the

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variable quest to is not equal to yes

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we want Python to return.

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Come eat at my place.

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Great.

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So as you can see if this variable is not equal to yes we want Biden to return come eat at my place

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right now we have our two first questions.

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So the next thing with our if statement we're here we have what's happening in the case that this is

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true but in the case that this is false in the case that it's equal to yes what what exactly from Biden

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we want from him to print us.

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Next question.

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Once again the print next question is.

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Well we are not in the obligation to use it but once again it's it could be a good thing to use it right.

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We could work without the L statement here.

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We can just go with the if statement and then jump directly to the quest number two but once again we

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want that we'll have it.

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It's gonna be more let's say more cool.

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I find it more cool to write at them.

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Right.

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So next thing we go to the last question that we'll have.

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So once again we'll have our last question in this case what we want to do we'll do the exact same thing.

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We store our variable which will be quest treat.

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So question number three and in this case the last question will be do you.

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What do you want to eat a pizza to input once again.

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And we ask our user do you want to eat a pizza

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so in this case if our user

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tells us that he wants to eat it he wants to eat it pizza.

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Tell him let's go eat a pizza in the case that he tells us that he don't want to eat a pizza we'll tell

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him let's go eat a burger.

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So sorry not no.

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Yes.

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All right.

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So in the case that our user tell us no or the answer is not equal to yes we will return.

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Let's go eat a burger then

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go eat a burger then great.

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And in the case that the answer is yes we will return fancy and print.

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Let us go at the let's go eat pizza.

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So right now we have absolutely everything that we need to be able to run our app.

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So let me just summarize everything that we just wrote.

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So once again we started with Def def means the opening of a function.

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So we write down our function the name of the function which has questions and what is inside of our

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function.

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Very simple.

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We have the rules so input.

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You need to answer every question by yes or no the first.

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So right now we have our variable here rules.

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So if the variable rules is equal to yes is not equal to yes sorry we return try again if it's equal

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to yes we return next question and we go to the next question.

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So in this case next question will be are you hungry.

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If are you hungry.

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Is not equal to yes we return then let's go for a walk.

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If it's equal to yes we return.

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Next question and we do the same thing for question number two in question number three so let's run

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up and see what it looks like.

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So as you can see if we just click it doesn't work.

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So the way that we have to run our app is very simple we write down a question right here.

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So we write down the name of our function there.

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We run our up once again.

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Let's do this.

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So first question you need to answer every question by yes or no do you understand.

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So let's say we write down no.

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As you can see.

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Try again and it stops.

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If we run our app and says and say yes.

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Next question.

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Are you hungry.

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So in this case yes I am.

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Next question Do you want to eat at a restaurant.

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Let's say I write the note.

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Come eat at my place.

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And this is where the app stops.

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So once again you can write to points everywhere just to make it more beautiful and more presentable.

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But besides of that you see guys how all this works.

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So it's very very simple.

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So we run the app another time just to be sure at 100 percent.

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Everything works perfectly.

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So let's run the app.

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So you need to answer every questions we understand.

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Yes I understand.

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Are you hungry.

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So in this case let's say yes.

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Do you want to eat at a restaurant.

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Yes.

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Do you want to eat a pizza.

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Let's say.

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No let's go eat a burger then.

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So as you can see every time that I answer yes it goes.

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Next question.

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If I answer No everything stops here.

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So this is the goal of this app once again we just ask questions to our users.

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And as you can see it's something very very basic.

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Once again it puts everything that you guys just learned into practice.

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So I hope you guys right now understand much much better the if statement and how to use it you understand

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functions and everything because it's a very very important part of Python.

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So right now wrote a very simple code but you'll see the more will advance in the course the more you'll

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learn things so you'll need to remember.

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Absolutely.

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Well you'll need to remember everything.

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If you want to be good in programming so I'll suggest you to practice with me every time that we do

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small exercises like this.

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So that's it for the slides guys.

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And see in our next class.