Understanding Inheritance

Reusing Code

One of the greatest strengths of OOP is Inheritance. It allows a new class to take on the attributes and methods of an existing class.

This helps avoid repeating code. For example, both a Cat and a Dog are Animals. Instead of writing “eating” logic for both, we can write it once in an Animal class.

Parent and Child Classes

• Parent Class (Base Class): The existing class you are inheriting from.
• Child Class (Derived Class): The new class that inherits from the parent.

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

    def eat(self):
        print(f"{self.name} is eating...")

# Dog inherits from Animal
class Dog(Animal):
    def bark(self):
        print("Woof!")

my_dog = Dog("Buddy")
my_dog.eat()  # Inherited from Animal
my_dog.bark() # Defined in Dog

Overriding Methods

A child class can provide its own version of a method that already exists in the parent. This is called Overriding.

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class Animal:
    def make_sound(self):
        print("Generic animal sound")

class Cat(Animal):
    def make_sound(self):
        print("Meow!")

my_cat = Cat()
my_cat.make_sound() # Prints "Meow!"

Using super()

Sometimes you want to keep the parent’s logic but add something extra to it. The super() function allows you to call methods from the parent class.

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

class Dog(Animal):
    def __init__(self, name, breed):
        super().__init__(name) # Calls parent __init__
        self.breed = breed

my_dog = Dog("Rex", "Husky")
print(my_dog.name)

Interactive Practice

Think of a Vehicle parent class. What child classes could it have? (Car, Bicycle, Plane). What methods would they share (e.g., move) and which would be unique (e.g., fly)?