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The first thing to do when creating a class is to

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actually define what attributes and what methods

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you need to put into the class. Well, that's what

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we have just done in the previous lesson. So now

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we can start the implementation with Python code.

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And let's write our first class, Robot. So I have

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created a new file here, doesn't really matter for

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the name, so for example, and to create a class it

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is very simple, you use the class keyword, and

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then the name of the class and then colon. So

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class keyword name of the class, colon, and for

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the name of the class, we are going to use a

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different convention than before. Here, you are

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going to use an uppercase letter, okay, for each

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new word, okay, and if you have different word,

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for example, RoboticArm that we're going to see

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later, well, you're going to put an uppercase for

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each new word. Alright, that's the convention.

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And then you press enter, and you can see that we

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have a new indentation of four spaces here. So

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you're going to write your class directly here

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with the indentation, okay, so everything that is

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indented is inside the class, everything that is

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not indented after that is outside of the class.

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And well, the first thing we have to do in this

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Python class is to create a constructor. The

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constructor is a method. Okay, so that's a

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function for a class. So this is a method, which

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will be called first when you create an object

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from the class. Because remember, a class is just

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a structure, it does nothing by itself. You will

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need to create some objects, so you can use the

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functionalities of the class. And when you create

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an object from the class, the first thing that is

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called is the constructor. And we're going to see

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just a little later how to create an object, now

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let's focus on the constructor. So the constructor

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will always be the same def. So you create def,

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like you just create a function, and then

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__init__,

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and then you open parentheses, okay, I

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have the auto completion here, the first

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parameter, you are going to give his self. Okay, I'm

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going to explain self just a bit later. And then

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you can add different parameters. So basically,

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the constructor will be called first when you

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create an object. So that can be a good point to

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initialize your attributes. And so you're going to

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pass the attributes of the class in the

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constructor parameters. So for example, we have

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name, version_number that we want to give to the

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Robot. Okay, I'm going to press Enter here. And

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of course, we have a new indentation for this

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function. So the function, so the method here is

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indented inside the class Robot, and then we have

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yet another indentation here. And what I'm going to

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do, I'm going to initialize the attributes by

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using self.name is equal to name, and then

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self.version_number is equal to version_number.

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And then I'm going to add self.internal_temperature

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is equal to and let's put just an

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arbitrary number, let's say 25, as a float. So

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here in the constructor of the class, we

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initialize the attributes of the class, okay, and

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to initialize the attributes, we actually to

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create some new variables with self, okay. So, for

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each method of the class, you are going to have

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first the self parameter. So when you use self,

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this actually refers to the object, okay, related

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to class Robot. And well, how to make the

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difference between a simple variable and an

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attribute of the class? Well for an attribute of the

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class you're simply going to use that self and to

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self., and then for example, name. So here, the

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name is the parameter. So this is a local variable

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inside this method, okay, if you remember from the

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scope. self.name, is actually in the class.

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So if I use another method, I'm going to see that

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just later, I'm going to be able to retrieve the

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self.name because this is inside the class of

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inside the object Robot that we have created with

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the constructor here. Alright, so to recap, you

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create a class with the class keyword and then the

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name colon, and then you're going to use different

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functions are listed here, indented inside the

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class. And the first internal method is the

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constructor, which is the init method. All right,

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we have now created a class structure for the

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Robot, and we have successfully created the

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attributes inside the class constructor.