? Python Inheritance

⚡ Quick Overview

Inheritance lets one class (the child or subclass) reuse and extend the behavior of another class (the parent or base class). This helps you:

• Promote code reusability by sharing common logic in a base class.
• Create hierarchical relationships like Animal → Dog → Puppy.
• Customize behavior using method overriding and super().

? Key Concepts

• Parent/Base class – class whose features are inherited (e.g., Animal).
• Child/Derived class – class that inherits from the parent (e.g., Dog(Animal)).
• Single inheritance – child inherits from one parent.
• Multiple inheritance – child inherits from more than one parent class.
• Method overriding – child class provides its own version of a parent method.
• super() – used to call parent methods/constructors from the child class.
• MRO (Method Resolution Order) – the order in which Python searches classes in multiple inheritance.

? Syntax and Theory

Basic inheritance syntax in Python:

class ChildClass(ParentClass):
The child class name is followed by the parent class in parentheses.

With constructor and super():

super().__init__(args) is used inside the child to call the parent’s __init__.

? Code Examples

?‍?‍? Basic Inheritance Example

Here, Dog inherits from Animal, so it can use both its own methods and the parent’s methods.

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

    def speak(self):
        print(f"{self.name} makes a sound.")

# Child class
class Dog(Animal):
    def bark(self):
        print(f"{self.name} says Woof!")

dog1 = Dog("Buddy")
dog1.speak()  # Inherited from Animal
dog1.bark()   # Defined in Dog

? Overriding Methods

The child class can override a method from the parent class to change its behavior for that specific child.

class Cat(Animal):
    def speak(self):   # Overriding parent method
        print(f"{self.name} says Meow!")

cat1 = Cat("Whiskers")
cat1.speak()  # Whiskers says Meow!

? Using super()

Use super() to call the parent’s version of a method, then extend it with extra behavior.

class Bird(Animal):
    def __init__(self, name, color):
        super().__init__(name)  # Call parent constructor
        self.color = color

    def speak(self):
        super().speak()  # Call parent method
        print(f"{self.name} chirps beautifully!")

bird1 = Bird("Parrot", "Green")
bird1.speak()

? Multiple Inheritance

A class can inherit from multiple parents. Python will follow the Method Resolution Order (MRO) to decide which parent to search first.

class CanFly:
    # Provides flying ability
    def fly(self):
        print("Flying high!")

class CanSwim:
    # Provides swimming ability
    def swim(self):
        print("Swimming smoothly!")

class Duck(CanFly, CanSwim):
    # Inherits both flying and swimming
    pass

duck1 = Duck()
duck1.fly()   # Uses fly() from CanFly
duck1.swim()  # Uses swim() from CanSwim