Inheritance

Sometimes classes are similar.

Instead of repeating the same code, one class can inherit from another class.

This is called inheritance.

What Is Inheritance?

Inheritance means a new class can use code from an existing class.

The existing class is called:

• parent class
• base class

The new class is called:

• child class
• derived class

Why Inheritance Matters

It helps you:

• reuse code
• reduce repetition
• organize related classes
• build larger programs

Real Example

A dog and cat are both animals.

Both may have:

• name
• eat()

But each can also have unique actions.

Parent Class

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

Child Class

class Dog(Animal):
    pass

pet = Dog()
pet.eat()

Output

Eating

Dog inherited eat() from Animal.

Add New Child Method

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

class Dog(Animal):
    def bark(self):
        print("Woof")

pet = Dog()
pet.eat()
pet.bark()

Output

Eating
Woof

Another Example

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

class Car(Vehicle):
    def drive(self):
        print("Driving")

car = Car()
car.start()
car.drive()

Output

Started
Driving

Inheriting init()

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

class Student(Person):
    pass

tom = Student("Tom")
print(tom.name)

Output

Tom

Why This Is Powerful

You write common code once in the parent class.

Children reuse it.

Code Along

Create a class Device with method power_on().

Create child class Phone.

Run the inherited method.

Mini Challenge

Create:

• Parent class Employee

  • method work()

• Child class Manager

  • method lead()

Create one manager object and run both methods.

Expected output:

Working
Leading

Real World Use Case

Apps use inheritance for users/admins, vehicles/cars, employees/managers, enemies/bosses, and UI components.

Quiz

1. What is inheritance?
2. What is a parent class?
3. What is a child class?
4. Why is inheritance useful?

Assignment

Create a parent class Animal with method sleep(). Create child class Cat.

Summary

You learned how child classes inherit code from parent classes to reduce repetition and organize programs.