Method Overriding in Python

Method overriding is a feature in object-oriented programming (OOP) that allows a subclass (child class) to provide a specific implementation of a method that is already defined in its superclass (parent class). When a method in a child class has the same name, parameters, and return type as a method in its parent class, the child class's method overrides the parent class's method.

Key Features of Method Overriding

1. Customization: It allows a subclass to modify or extend the functionality of a method inherited from its parent class. This is useful when the behavior of a method needs to be specific to the child class.

2. Dynamic Polymorphism: Method overriding is a form of dynamic polymorphism, where the method that gets executed is determined at runtime based on the object's class.

3. Method Resolution Order (MRO): When a method is called, Python follows the MRO to find the appropriate method to execute, starting from the child class and moving up to the parent classes.

Example of Method Overriding

Here’s an example to illustrate method overriding in Python:

# Parent class
class Animal:
    def speak(self):
        return "Animal speaks"

# Child class inheriting from Animal
class Dog(Animal):
    def speak(self):  # Overriding the parent's speak method
        return "Dog barks"

# Child class inheriting from Animal
class Cat(Animal):
    def speak(self):  # Overriding the parent's speak method
        return "Cat meows"

# Creating instances of Dog and Cat
my_dog = Dog()
my_cat = Cat()

# Calling the overridden methods
print(my_dog.speak())  # Output: Dog barks
print(my_cat.speak())  # Output: Cat meows

Explanation of the Example

1. Parent Class (Animal):

   • The Animal class has a method speak() that returns a generic message indicating that an animal speaks.

2. Child Class (Dog):

   • The Dog class inherits from Animal and overrides the speak() method to provide a specific implementation that returns "Dog barks".

3. Child Class (Cat):

   • The Cat class also inherits from Animal and overrides the speak() method to return "Cat meows".

4. Creating Instances: Instances of Dog and Cat classes are created.

5. Method Access: When the speak() method is called on each instance, the overridden method in the respective child class is executed, demonstrating how the child class can define its specific behavior.

Summary

• Method overriding is a powerful feature that allows a subclass to provide its specific implementation of a method defined in its superclass.
• It promotes flexibility and enables the design of more specific behaviors for subclasses, while still retaining the general structure provided by the parent class.
• The process supports dynamic polymorphism, allowing for method resolution at runtime based on the actual class of the object.

If you have any further questions or need more examples, feel free to ask!