Python Inheritance

Inheritance models an "is a" relationship between classes. A more specific class, called the child or subclass, builds on a more general class, called the parent or base class. The child automatically gains everything the parent defines and may add new features or change existing ones. This keeps shared logic in one place instead of repeating it across similar classes.

Creating a subclass

You declare inheritance by writing the parent class name in parentheses after the child class name. In the example, Cat inherits the describe method from Animal without redefining it, because a cat is a kind of animal.

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

    def describe(self):
        return f"{self.name} is an animal."

class Cat(Animal):
    def meow(self):
        return f"{self.name} says meow."

c = Cat("Milo")
print(c.describe())   # inherited: Milo is an animal.
print(c.meow())       # new: Milo says meow.

Overriding methods and using super()

A subclass can replace a parent method by defining one with the same name; this is called overriding. Often you still want the parent's version to run as part of the new one, and super() gives you access to it. This is common in __init__ when the child needs the parent's setup plus its own.

class Vehicle:
    def __init__(self, brand):
        self.brand = brand

    def info(self):
        return f"Vehicle brand: {self.brand}"

class Car(Vehicle):
    def __init__(self, brand, doors):
        super().__init__(brand)   # run the parent's __init__
        self.doors = doors

    def info(self):
        base = super().info()      # reuse the parent's method
        return f"{base}, doors: {self.doors}"

my_car = Car("Toyota", 4)
print(my_car.info())   # Vehicle brand: Toyota, doors: 4

• Inheritance expresses an "is a" relationship and promotes reuse.
• Write the parent name in parentheses to inherit from it.
• Override a method by defining one with the same name in the child.
• Call super() to reuse the parent's implementation.