Purpose of inheritance in Python

Introduction

Inheritance helps us reuse code by letting one class get features from another. It makes programs easier to build and understand.

When you want to create a new class that is a special version of an existing class.

When you want to share common code between different classes without copying it.

When you want to organize related classes in a clear way.

When you want to add new features to an existing class without changing it.

When you want to fix or improve behavior of a class by making a new version.

Syntax

Python

class ParentClass:
    # parent class code

class ChildClass(ParentClass):
    # child class code

The child class gets all the features (methods and variables) of the parent class.

You can add or change features in the child class without touching the parent.

Examples

Dog inherits from Animal but changes the speak method.

Python

class Animal:
    def speak(self):
        print("Animal speaks")

class Dog(Animal):
    def speak(self):
        print("Dog barks")

Car inherits start method from Vehicle without changes.

Python

class Vehicle:
    def start(self):
        print("Vehicle started")

class Car(Vehicle):
    pass

Sample Program

Student inherits greet from Person and adds study method.

Python

class Person:
    def greet(self):
        print("Hello!")

class Student(Person):
    def study(self):
        print("Studying hard")

s = Student()
s.greet()
s.study()

Important Notes

Inheritance helps avoid repeating code.

Child classes can use or change what they get from parents.

Use inheritance to show 'is-a' relationships, like Student is a Person.

Summary

Inheritance lets one class get features from another.

It helps reuse code and organize programs better.

Child classes can add or change features from parent classes.