How does inheritance and method overriding work in Python?

Short answer

Inheritance allows a class to acquire attributes and methods from a parent class. Override methods in the child class to customize behavior, and use super() to call the parent implementation.

Steps

1. Define a base class.
2. Define a subclass that inherits from the base class.
3. Override methods as needed and call super().method() to extend parent behavior.

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

    def speak(self):
        raise NotImplementedError("Subclasses must implement this")

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

    def speak(self):
        return f"{self.name} says meow!"

whiskers = Cat("Whiskers", "gray")
print(whiskers.speak())

Tips

• Python supports multiple inheritance; the Method Resolution Order (MRO) determines which parent method is called.
• Use isinstance(obj, Class) to check if an object inherits from a class.
• Abstract base classes (ABCs) from the abc module enforce that subclasses implement certain methods.

from abc import ABC, abstractmethod

class Shape(ABC):
    @abstractmethod
    def area(self):
        pass

class Circle(Shape):
    def __init__(self, radius):
        self.radius = radius

    def area(self):
        import math
        return math.pi * self.radius ** 2

Common issues

• Forgetting to call super().__init__() leaves inherited attributes uninitialized.
• Diamond inheritance can lead to confusing MRO; use ClassName.__mro__ to inspect the order.
• Overriding a method accidentally (e.g., naming it the same as a parent method) can break expected behavior.