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Classes in Python are how you make objects.

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The classes themselves are the blueprint for how an object is created.

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For example, here is a class called Duck.

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And it implements a couple of methods called quack and walk, so that when you

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create a duck object, that duck will quack like a duck and walk like a duck and

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that of course will make it a duck.

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An object is an instance of a class.

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That means that when you create an object, it's a separate thing.

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It's separately encapsulated.

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It has all of its own attributes.

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So if you make several different objects from a given class, each of those

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different instance of the class, but they're all separately encapsulated and

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have their own data space, their own code space and are essentially their own objects.

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An object is an instance of a class.

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That means when you create an object, that object is built from the blueprint of

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the class, but it's its own object.

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Its own encapsulation.

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And so if you create several different objects from the same class,

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they're separately encapsulated.

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They have their own data space and they have their own attributes, and they

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operate independently of one another.

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So in this case, we've created an object called donald from the Duck class.

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And we can say donald.quack and donald.walk.

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And donald will quack like a duck and will walk like a duck and therefore is a duck.

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Let's take a look at how this works in practice.

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So we'll start by making a working copy of classes.py, and we'll call

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it classes-working.py.

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Go ahead and open that working copy.

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And we see we have our Duck class and we have donald.

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So if we go ahead and run this, you'll see that donald quacks like a duck and

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donald walks like a duck.

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So let's take a look at how this works.

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Class is the keyword that introduces the definition of a class.

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Duck here is the name of the class and then there is a colon, and so because

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there is a colon, you have things that are indented under this level.

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And those are the suite of the class definition.

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And in this case we have two things inside the class.

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We have a function called quack and that function, because it has self as its

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first argument, is actually a method of the class.

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And we'll talk in a moment about how this works.

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Then we have walk, which is defined in the same way, and so that's another method.

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And then down here, when we create the object donald, we create the object

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donald by assigning it from Duck.

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And Duck is the class definition.

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And so now donald is an object.

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And donald is an object of the class Duck.

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So if I were to just go here and I were to say print(donald), like that, save

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that and run it, then it says <__main__.Duck object at.

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And so donald is an object of the class Duck.

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So when I call the quack method, I use this dot operator and that dot operator

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is the attribute dereference operator.

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That means that it's going to look inside the object donald for an

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attribute called quack.

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And because it has these parentheses on it, it's going to go ahead and call it

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as an object method.

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And so that will call this code, and it prints this quack, and donald.walk calls

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this code, and it prints that "Walks like a duck."

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So Duck is the class and that's all this stuff here, and donald is the object.

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He's an instance of Duck.

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And you can call the methods inside donald.

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And so you can call the methods inside the donald object of class Duck

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using this dot notation.

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So that's how you define a class and create objects based on it in Python.

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Python is fundamentally an object-oriented language.

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And that means you're going to do this a lot.

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There are times when you just have a single thing that you want to do and you

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want to do it in a very simple way.

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And for that, you'll just create a function and you'll use a function.

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Often you're going to want to do things that are more complicated and these

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more complicated things are going to have their own local data and they're

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going to have multiple methods that are tightly related to each other and

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interact with each other.

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And these are the times when we're going to go ahead and create a class and use objects.

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As you go through the process of writing programs in Python, especially if

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you've not worked with an object- oriented language before, you're going to see

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more and more cases where objects make sense.

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If you're used to using functions a lot, you'll be creating a lot of functions

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for things, but over time as you get more familiar with the power and the

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flexibility and the encapsulation and inheritance of the different properties of

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objects that we're going to go through in this chapter, you're going to use

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objects more and more.

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And you'll end up using objects for a lot of the things that you used to use

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multiple functions for.

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So objects are very powerful.

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Python is a fundamentally object- oriented language, so you're going to use these

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techniques often as you write code in Python.