In this tutorial we are going to learn :
- Classes in Python
- Creating A Class
- Constructors
- Private Members
Classes in Python
Python is an object-oriented programming language. Almost everything in Python is an object.
Important concepts :
- Class : helps us to create an object and it is simply a blueprint of an object.
- Object : an instance of a class.
- Method : A function which is created in the class.
- Attributes : A variable bound to an instance of a class.
Let’s give an example Class and Object
Class : Animal
Object : Cat, Dog, Bird.
Creating A Class
We use the class keyword to create a class.
Note :
Class name rule : First letter of each internal word should be upper case.
Example:
Constructors
The example programs above are classes and objects in their simplest form. To understand the meaning of classes we have to understand the constructors ( __init__ function ) .
- All classes have __init__ function and it is always executed when the class is being
initiated.
Example :
As you can see when we create a constructor and create variables we can access his variables from outside.
- the self parameter is a reference to the current instance of the object. So we can access the variables.
Example :
Example :
- The self parameter is a reference to the current instance of the class and we use to access variables that belong to the class.
Private Members
To make our variables private, we use double underscores ( __ ) .
Example :
- As you can see we can’t access our private name variable and our program raise an error.
