Polymorphism is a fundamental concept in object-oriented programming that allows objects of different classes to be treated as objects of a common superclass. It enables a single function or method to operate on different types of objects. In Python, polymorphism can be implemented using inheritance and method overriding.
What is Polymorphism?
Polymorphism means “many shapes” and it allows functions and methods to use objects of different types interchangeably. It provides flexibility and reusability in code by allowing the same interface to work with different underlying forms (data types).
Polymorphism with Inheritance
When a class inherits from another class, it can override methods of the parent class. This is a common way to implement polymorphism.
Base Class: Animal
class Animal:
def speak(self):
passDerived Class: Dog
class Dog(Animal):
def speak(self):
return "Woof!"Derived Class: Cat
class Cat(Animal):
def speak(self):
return "Meow!"Using Polymorphism
In the example above, the animal_sound function can take any object that belongs to a class derived from Animal and call its speak method.
def animal_sound(animal):
print(animal.speak())
dog = Dog()
cat = Cat()
animal_sound(dog) # Output: Woof!
animal_sound(cat) # Output: Meow!Polymorphism with Functions and Methods
Polymorphism isn’t limited to class inheritance. It can also be achieved through functions and methods that work with different types of data.
Example: Polymorphic Function
In this example, the add function works with both integers and strings because the + operator is polymorphic and behaves differently based on the type of its operands.
def add(x, y):
return x + y
print(add(5, 10)) # Output: 15
print(add("Hello, ", "world!")) # Output: Hello, world!