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Oh yes.

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And welcome back to another class of our course about Python.

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So until now we talked about a lot of very interesting things.

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And until now you were supposed to have a pretty much good knowledge of python and how it works.

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So we talked in our best class about the if statement and how exactly it works.

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We talked about the if or statement we talked about the if and statement and basically everything what's

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around the if statement.

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And we also saw that the if statement works with the boolean.

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So usually you need a true or a false to be able to run an if statement which is true in the majority

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of cases but you don't really need the statement in itself to be able to run an IF function.

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Let me explain myself so you can compare it let's say for example when you compare a number to another

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number.

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Normally you will have a true or false value.

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So for example if you compare one with one well one equals to one.

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And in this case you have your if statement.

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So this statement means it's true because 1 equals 2 1 So this is the same thing for for our well for

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our what we will do today.

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So my goal today is really to present you guys how exactly we can work with the if statement without

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necessarily having a true or false values or boolean values.

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So let's try this out.

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So the first thing.

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So we'll we'll do some of the also two basic exercises with variables and then after that we'll go and

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work with some more advanced data.

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So let's start the first thing that I will do.

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We can just watch for now.

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I'll have two variables so I'll have verbal number one which will be equal to one and viable number

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two which will be equal to five.

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I'll write down my if statement.

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So in this case if variable number one is equal to variable number five a variable number two.

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Sorry I want to print.

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Yes

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otherwise

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I want to print.

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No.

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So in this case print.

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No.

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If I run the app so just over two points.

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If I run my app as you can see the answer will be no.

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Why.

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Because variable number one is not equal to variable number two.

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And in this case if for example I write down five.

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So if I won my app it's gonna be yes.

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So as you can see I don't necessarily have the true or false statement and nowhere no statements are

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the true or false data nor where there is stored in any variable but instead I have let's say numbers.

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So I compare one number to another number and because they are you one not the first number is equal

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to the same number.

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This means that it's true.

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So this value is true.

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So this theoretically equals 2 true.

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And because of that python will print.

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Yes I can do it more eventually for example I can even have let's say three variables or in this case

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three variables and let's say all right.

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Equal to to I can even print something like this equal to variable number three and I can run my app

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and as you can see the value will be no.

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Why.

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Because Bible number one is equal to Bible number two but is not equal to viable number three.

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So what I can use is another statement which is not equal to verbal.

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Number three.

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So if I run my app it's gonna be yes.

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Why.

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Because Bible number one is equal to Bible number two but not equal to verbal number three so if you

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want to write equal it's gonna be two equal signs if you're on the right don't not equal it's gonna

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be an exclamation mark and an equal sign.

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All right.

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So right now you get the point of all this.

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Let's try something else.

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Let's say for example here I'll have five and six instead of equal what I can do is I can write greater.

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So let's say for example Bible number one is greater than Bible number two.

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And two points.

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Once a year.

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If I run my app as you can see Bible number one is not greater than variable number two.

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So in this case the answer will be no.

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But what I can do also I can say for example equal or greater or equal.

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So in this case if I run it it's going to be no but if it's five it's gonna be yes because it's equal.

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So in this case I would ask if it's greater or equal.

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Well it's equal.

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So devout the answer will be yes you can do this for greater for equal for greater or equal for smaller

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equal can do this for many many.

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Well there are many comparisons that exist.

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But the most popular ones are equal not equal greater smaller greater or equal smaller or equal.

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All right.

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So right now that you understand what exactly are is the comparison part in the if statement I propose

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we guys to make two basic apps so you'll be able to practice and understand it a little bit more.

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So let's jump in.

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So the first thing I'll ask you guys to do is open up your wallet.

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You already on so on Europe your text editor and what you will do is create four variables.

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So we'll have one and we'll use colors so we'll use string.

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You can use colors or any other type of string.

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Doesn't matter.

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So we have 4 1 4 2

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right.

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So we have everything what we need that we need

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after that you simply add the colors that you want to add.

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So in my case it's gonna be blue red black and yellow.

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Great

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I have what I need.

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So I will do right now.

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Also my goal right now is simply to show you that you can compare strings together.

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So five seconds ago we compared numbers together but right now we'll compare strings together.

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So for example if we write down our if available once again a function sorry.

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We have our variable number one which is for example equal to level number two in the case that it's

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true.

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What we'll do we want Python to return.

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Print.

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Yes.

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It's the same color.

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Great

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so we run our app and we have nothing because it's not the same.

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So what will be our same condition.

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Else if it's not true.

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Once Python to print.

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No no it's not true enough or yet very important.

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You're two points when it's all done simply run your app.

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So as you can see the answer is no it's not true.

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Because Bible number one is not equal to Bible number two if for example.

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Here we have red.

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So red is equal to red.

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We run our app.

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Yes it's the same color.

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So we can if it is the same thing it's going to tell you this but let's say for example we have red

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with a capital letter and red with the small letter.

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It's not going to work.

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Why.

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Because Python respects kept the letters.

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So if you have two words but the letters one it's in the capital the other is not it's not gonna work.

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So very important you need the exact same thing if you want it to work.

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All right.

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So right now you get the point that you can compare strings together you can compare numbers together

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you can compare boolean together you can compare absolutely everything together but you can't compare

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string with numbers or numbers with that for example Boolean if for example you want to compare numbers

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with strings and you need to transform your string into a number before being able to do it and you

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have some functions do it.

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All right we will.

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So let's create another small app.

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This time it's going to give him the app will be a bit more complex since I want you guys to practice

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a bit more but that in this app what we'll do principally is very simple.

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Our goal is to find out who is the richest person between the three different persons.

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So what exactly we'll have to do right now the first thing we'll need to find out the name of each person.

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So we'll ask users to enter their names and enter how much money they have.

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So let's write it down.

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So we have our first variable which will be a person's name.

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So we have divided it looks like this equal input.

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So we have our input and we'll ask our user to do is what is your name.

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So right here the user will enter his or her name from now the next thing that we want to know from

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this user is how much money do you have.

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So we'll treat another variable that will name person's wallet the state's purse wallet and we'll write

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down input and ask the person how much money do you have.

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Right.

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So the better the person will answer us with his or her name and the money that that this person as

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you can.

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Right now what we need to do is the exact same thing for the two next persons because we'll have three

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different persons so you can simply copy everything and past it and instead of having person number

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one we'll have person number two.

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Great.

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So we do this for person number two and person number three as well.

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All right.

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So until now you have everything you need to be able to continue.

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So if person number one number two and number two write down that we have our basic database.

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It's time for us to create our app.

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So once again we'll use the if function in this app to be able to run it.

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So what we will ask well will ask Python to do right now.

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Very simple.

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We want to know what the name of the person end if the person number one has more money than the person

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number two.

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If yes we want to verify if Person number one has more money than person number three.

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If those two statements are respected we'll simply return person number one is the richest.

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So very very simple as you can see the app is simple.

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Right now it's time to create it.

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So we'll have our if statement right here and the first thing that will need to enter right now is we

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need to convert our strings into numbers so as I explained before you can't work with strings and numbers

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at the same time because Python can compare strings with numbers.

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So very important to convert to convert it first.

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So how do we convert strings to numbers with the float functions that don't float open up your parentheses

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and you copy this variable right here.

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So if person number one while it equal in this case to Person number two wallet now for you have to

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write down your float function because without it nothing will work.

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You'll have errors.

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So.

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All right.

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We have float person number one wallet greater than Person number two.

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Well so this is the first part of the function we verify if it's true then we want to verify if the

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person number one has more money than the person number tweet as well.

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So we'll use the end function here.

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We'll use if and and we'll write down our float to be able to work with the numbers.

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So person number one wallet is greater than

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Person number two well all right so we have everything we need.

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We write down our two points and we jump.

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So next question.

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Next thing that we need to do right now that we have our first function ready is our output right.

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Our output.

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So very simple what one python to print right now.

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So very simple.

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We print person number one name.

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So we need the name of the person number one plus is the richest.

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So is the richest.

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So we have our inputs right here.

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We have our database right here so everyone enters his name.

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And how much money he has.

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The calculation right here.

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So person number one wallet greater than Person number two same thing for a person number three

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and then we print the name of person number one is the richest if it's true if it's false if it doesn't

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work what we need to do right now is very simple.

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So we verify if it's number two the person number two is the richest.

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So in this case we'll use the Elif function once again it's an if function that is integrated in another

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function.

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So we do the exact same thing instead of free writing.

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Everything can simply copy it and post it here then the next thing that you guys need to do is changing

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the name of people.

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So here we'll have Person number two is richer than person number one.

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Same thing here.

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Person number two in number three and in the name not forget the right person number two as well

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and finally you copy and paste everything to be able to do the exact same thing for person number two

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when we have all this what we can do now we can run up.

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So we have absolutely everything we have our condition so our logical test for Person 1 2 and 3 and

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we can run our up to see what it looks like.

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So what is your name.

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In this case name will say Jack how much money Jack has one hundred dollars.

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What is your name.

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I don't know.

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Meaning how much money Mina has.

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Fifty dollars.

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And finally what is your name.

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So let's say John.

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How much money John has.

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Twenty five dollars.

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We run our app.

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Jack is the richest.

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Which makes sense.

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Let's change our inputs.

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In this case what's earning.

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Once again we'll say Jack

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how much money do we have Jack.

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Ten dollars.

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Mina how much money do you have.

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Fifty dollars.

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And finally what's your name.

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Let's say John.

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How much money do you have John.

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Fifteen let's say fifteen dollars.

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We run the app.

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Mina is the richest as you can see Isaac is very very simple.

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The app works perfectly we can find who is the richest person.

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So until now you know how you can use the if statement the if statement is really for decision making.

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And right now you can see that you don't necessarily need the Boolean value the true and the false rate

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in somewhere or stored somewhere in a variable.

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You can just compare a you can compare a string with a string and expect to have a true or false value

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so let's say for example if two things are not the same or it doesn't respect the comparison.

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Well this means it's not true.

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And if it respects it well this means it's true.

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So let's say a number is greater than another number.

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Well this means it respects the comparison of this number is greater than this number.

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So in this case it's true.

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So I hope you guys understand right now that you can work with the if statement this week and this will

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be very very useful for you guys in the future when you will become more advanced in this programming

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language.

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So that's it for this class.

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Guys see you all in our next class.