L13 Inheritance

Imagine a family where children inherit traits from their parents. In Python, inheritance works similarly—one class can inherit attributes and methods from another.

This means we don’t have to rewrite common features. Instead, we create a parent class, and new classes (children) can build upon it, saving time and making the code more efficient.

💡 Analogy: Inheritance is like hand-me-down clothes—new generations (child classes) inherit features from the old ones (parent class) but can still make modifications.

Learning Objectives

By the end of this lesson, you will be able to:

1. Understand inheritance in OOP.

2. Create child classes that inherit from parent classes.

3. Override methods in a child class.

Key Terms

• Inheritance – A mechanism that allows a child class to inherit attributes and methods from a parent class.

• Parent class – The base class that provides attributes and methods to other classes.

• Child class – A class that inherits from another class, extending its functionality.

• super() function – Calls the constructor of the parent class inside a child class.

• Method overriding – Redefining a method in a child class to change its behavior.

Example 1: Creating a Parent and Child Class

class Vehicle:

    def __init__(self, brand, model):

        self.brand = brand

        self.model = model

class Car(Vehicle):

    def __init__(self, brand, model, doors):

        super().__init__(brand, model)

        self.doors = doors

car1 = Car("Toyota", "Corolla", 4)

print(car1.brand)  # Output: Toyota

🛑 Common Mistakes

1. Forgetting to use super() to inherit attributes from the parent class.

2. Redefining a method without calling the parent version when needed.