https://www.geeksforgeeks.org/types-of-inheritance-python/
* An abstract class can be considered as a blueprint for other classes. * It allows you to create a set of methods that must be created within any child classes built from the abstract class. * A class which contains one or more abstract methods is called an abstract class. * An abstract method is a method that has a declaration but does not have an implementation. While we are designing large functional units we use an abstract class. When we want to provide a common interface for different implementations of a component, we use an abstract class.
By defining an abstract base class, you can define a common Application Program Interface(API) for a set of subclasses. This capability is especially useful in situations where a third-party is going to provide implementations, such as with plugins, but can also help you when working in a large team or with a large code-base where keeping all classes in your mind is difficult or not possible.
By default, Python does not provide abstract classes. Python comes with a module that provides the base for defining Abstract Base classes(ABC) and that module name is ABC. ABC works by decorating methods of the base class as abstract and then registering concrete classes as implementations of the abstract base. A method becomes abstract when decorated with the keyword @abstractmethod. For Example
from abc import ABC, abstractmethod class Polygon(ABC): @abstractmethod def noofsides(self): pass class Triangle(Polygon): # overriding abstract method def noofsides(self): print("I have 3 sides") class Pentagon(Polygon): # overriding abstract method def noofsides(self): print("I have 5 sides") class Hexagon(Polygon): # overriding abstract method def noofsides(self): print("I have 6 sides") class Quadrilateral(Polygon): # overriding abstract method def noofsides(self): print("I have 4 sides") # Driver code R = Triangle() R.noofsides() K = Quadrilateral() K.noofsides() R = Pentagon() R.noofsides() K = Hexagon() K.noofsides() Output: