Python Inheritance Complete Guide

What is Inheritance?

Inheritance is an OOP concept where one class acquires properties and methods of another class.

• Parent Class / Base Class -> Existing class
• Child Class / Derived Class -> New class that inherits features

Real-Life Example

• Father -> Parent class
• Son -> Child class

The child inherits qualities from the parent.

Why Use Inheritance?

• Code reusability
• Reduces duplication
• Easy maintenance
• Better organization
• Supports hierarchical relationships

Basic Syntax

class Parent:
    pass

class Child(Parent):
    pass

Simple Inheritance Example

class Animal:
    def eat(self):
        print("Animal eats food")

class Dog(Animal):
    pass

d = Dog()
d.eat()

Output: Animal eats food

The Dog class inherited the eat() method from Animal.

Types of Inheritance in Python

• Single Inheritance
• Multiple Inheritance
• Multilevel Inheritance
• Hierarchical Inheritance
• Hybrid Inheritance

1. Single Inheritance

One child inherits from one parent.

class Parent:
    def display(self):
        print("Parent class")

class Child(Parent):
    pass

obj = Child()
obj.display()

2. Multiple Inheritance

One child inherits from multiple parents.

class Father:
    def skills1(self):
        print("Driving")

class Mother:
    def skills2(self):
        print("Cooking")

class Child(Father, Mother):
    pass

c = Child()
c.skills1()
c.skills2()

3. Multilevel Inheritance

Inheritance chain across multiple levels.

class Grandparent:
    def house(self):
        print("Grandparent house")

class Parent(Grandparent):
    def car(self):
        print("Parent car")

class Child(Parent):
    def bike(self):
        print("Child bike")

c = Child()
c.house()
c.car()
c.bike()

4. Hierarchical Inheritance

Multiple child classes inherit from one parent.

class Animal:
    def eat(self):
        print("Eating")

class Dog(Animal):
    pass

class Cat(Animal):
    pass

d = Dog()
c = Cat()
d.eat()
c.eat()

5. Hybrid Inheritance

Combination of multiple inheritance types.

class A:
    pass

class B(A):
    pass

class C(A):
    pass

class D(B, C):
    pass

Using super() Method

super() calls parent class constructor or methods.

Example of super()

class Parent:
    def __init__(self):
        print("Parent constructor")

class Child(Parent):
    def __init__(self):
        super().__init__()
        print("Child constructor")

c = Child()

Output:
Parent constructor
Child constructor

Constructor Inheritance

class Person:
    def __init__(self, name):
        self.name = name

class Student(Person):
    def show(self):
        print(self.name)

s = Student("Rahul")
s.show()

Method Overriding in Inheritance

Child class can modify parent method.

class Animal:
    def sound(self):
        print("Animal sound")

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

d = Dog()
d.sound()

Method Resolution Order (MRO)

MRO decides the order in which classes are searched in multiple inheritance.

class A:
    pass

class B(A):
    pass

class C(A):
    pass

class D(B, C):
    pass

print(D.mro())

Advantages and Disadvantages of Inheritance

Advantages of Inheritance

• Reusability
• Saves time
• Easier debugging
• Better program structure
• Supports polymorphism

Disadvantages of Inheritance

• Tight coupling
• Complex hierarchy can confuse developers
• Excessive inheritance reduces readability

Real-Life Examples