Python OOP Course

FreeCodeCamp.org: https://www.youtube.com/watch?v=Ej_02ICOIgs&t=327s

Object Oriented Programming:

Encapsulation:

Hiding data and restricting direct access to some of the object attributes. The idea is to protect information by applying indirect changes to data attributes using methods if necessary.

Abstraction:

Hiding internal implementation details and unnecessary information from the instances by making methods private. This can be done by adding double underscores __ in front of a variable name.

Inheritance:

The procedure in which one class inherits the attributes and methods of another class. This allow us to reuse codes across all classes.

Polymorphism:

Refers to the use of a single type entity to represent different types in different scenarios. For example, the len() function in python behaves differently when given different data types (objects). This is polymorphism in action.

Python Syntax

Class method is used to create objects with similar attributes to benefit from methods implemented within class.

def __init__(self):

It is used as a constructor of an object instance. We define the attributes shared commonly within the class when creating new instances. Note that self refer to the particular instance when calling the method.

@classmethod

It is used when there is a relationship with the class (not individual unique instances) and data structures manipulation is needed. For example, creating new object instances from a csv or json file.

@staticmethod

It is used where there is relationship with the class but not common between instances. Therefore, self object is not needed to pass on as an argument. It is like a regular function but defined within the class itself.

class child(parent):

The syntax to create a child class that builds upon the parent class

super()

This method is used in the __init__ method to inherit attributes from the parent class so we don't have to assign them repetitively. Note that it will also inherit the methods from the parent class.

@property

This decorator is used to declare read-only attribute.

@name.setter

Decorator used to set read-only attribute specified by property decorator.

self.__class__.__name__

Access the class name from an object instance.