Polymorphism Python

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What is Polymorphism?

Polymorphism means “many forms.” In Python OOP, it allows the same function or method name to behave differently based on the object or data type it is acting upon.

Real-Life Example

Think about the word “run”:

A person can run
A car can run
A program can run

Even though the action “run” is the same word, it behaves differently based on who or what is performing it. That’s Polymorphism.

Example 1: Built-in Polymorphism

Python supports polymorphism even with built-in functions.

print(len("Megha")) # String
print(len([10, 20, 30])) # List
print(len({"a": 1, "b": 2})) # Dictionary

▶ Output will appear here.

The same len() function works differently for strings, lists, and dictionaries.

Example 2: Polymorphism with Classes and Methods

polymorphism works with user-defined classes.

A subclass can override a method from its parent class.

class Bird:
 def intro(self):
 print("There are many types of birds.")
 def flight(self):
 print("Most birds can fly.")
class Penguin(Bird):
 def flight(self):
 print("Penguins cannot fly, they swim.")
# Objects
bird1 = Bird()
bird2 = Penguin()
bird1.intro()
bird1.flight()
bird2.intro()
bird2.flight()

▶ Output will appear here.

Here, the same method flight() behaves differently for different objects (Bird and Penguin).

Example 3: Polymorphism Using a Common Interface

Different objects can be passed to the same function, and the function will call their respective methods.

class Dog:
 def sound(self):
 return "Bark"
class Cat:
 def sound(self):
 return "Meow"
# Function showing polymorphism
def animal_sound(animal):
 print(animal.sound())
dog = Dog()
cat = Cat()
animal_sound(dog)
animal_sound(cat)

▶ Output will appear here.

Same function animal_sound()
Works for both Dog and Cat
That’s polymorphism through duck typing

Example 4: Polymorphism with Inheritance and super()

class Shape:
 def area(self):
 print("This method should be overridden by subclasses.")
class Circle(Shape):
 def area(self):
 print("Area = π × r²")
class Rectangle(Shape):
 def area(self):
 print("Area = length × width")
# Loop through different objects
for shape in [Circle(), Rectangle()]:
 shape.area()

▶ Output will appear here.

Both Circle and Rectangle override the same method area() — this is method overriding, a type of polymorphism.

Both classes provide their own version of area()
This is method overriding → a key form of polymorphism

Why Polymorphism Is Important?

Makes code flexible
Allows writing common interfaces
Supports method overriding
Key to writing clean OOP-based applications
Helps implement inheritance, interfaces, and abstract classes

Polymorphism Python

What is Polymorphism?

Real-Life Example

Example 1: Built-in Polymorphism

Example 2: Polymorphism with Classes and Methods

Example 3: Polymorphism Using a Common Interface

Example 4: Polymorphism with Inheritance and super()

Why Polymorphism Is Important?

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