Python Polymorphism

🐍 Python Polymorphism

Polymorphism is an OOP concept that means “many forms”.
In Python, it allows objects of different classes to be treated in a similar way.

1️⃣ Types of Polymorphism in Python

Duck Typing / Method Polymorphism (Same method name, different classes)
Operator Overloading (Same operator behaves differently)
Method Overriding (Child class method overrides parent method)

2️⃣ Duck Typing Example (Method Polymorphism)

class Dog:
def speak(self):
print("Woof! Woof!")

class Cat:
def speak(self):
print("Meow!")

def make_animal_speak(animal):
animal.speak() # works for any object with speak() method

d = Dog()
c = Cat()

make_animal_speak(d) # Woof! Woof!
make_animal_speak(c) # Meow!

class Dog:

def speak(self):

print("Woof! Woof!")

class Cat:

def speak(self):

print("Meow!")

def make_animal_speak(animal):

animal.speak() # works for any object with speak() method

d = Dog()

c = Cat()

make_animal_speak(d) # Woof! Woof!

make_animal_speak(c) # Meow!

Python is dynamically typed, so it doesn’t care about the object type.

3️⃣ Operator Overloading

Operators like +, -, * can behave differently depending on data types.

# Numbers
print(5 + 10) # 15

# Strings
print("Hello " + "World") # Hello World

# Custom Class
class Point:
def __init__(self, x, y):
self.x = x
self.y = y

def __add__(self, other):
return Point(self.x + other.x, self.y + other.y)

p1 = Point(2, 3)
p2 = Point(4, 5)
p3 = p1 + p2
print(p3.x, p3.y) # 6 8

# Numbers

print(5 + 10) # 15

# Strings

print("Hello " + "World") # Hello World

# Custom Class

class Point:

def __init__(self, x, y):

self.x = x

self.y = y

def __add__(self, other):

return Point(self.x + other.x, self.y + other.y)

p1 = Point(2, 3)

p2 = Point(4, 5)

p3 = p1 + p2

print(p3.x, p3.y) # 6 8

__add__ method allows overloading the + operator.

4️⃣ Method Overriding (Run-time Polymorphism)

Child class can override parent class method.

class Animal:
def speak(self):
print("Some generic sound")

class Dog(Animal):
def speak(self):
print("Woof! Woof!")

d = Dog()
d.speak() # Woof! Woof!


Can still call parent method using super():



class Dog(Animal):
def speak(self):
super().speak()
print("Woof! Woof!")

d = Dog()
d.speak()

class Animal:

def speak(self):

print("Some generic sound")

class Dog(Animal):

def speak(self):

print("Woof! Woof!")

d = Dog()

d.speak() # Woof! Woof!

Can still call parent method using super():

class Dog(Animal):

def speak(self):

super().speak()

print("Woof! Woof!")

d = Dog()

d.speak()

Output:

5️⃣ Polymorphism With Built-in Functions

Same function (len) works on different data types.

6️⃣ Summary Table

Type	Example
Duck Typing / Method Polymorphism	`speak()` in Dog & Cat
Operator Overloading	`+` behaves differently for int, str, objects
Method Overriding	Child class method overrides parent method
Built-in Function Polymorphism	`len()` works on strings, lists, tuples

7️⃣ Real-World Example: Payment System

class CreditCard:
def pay(self):
print("Paid using Credit Card")

class UPI:
def pay(self):
print("Paid using UPI")

def process_payment(method):
method.pay()

cc = CreditCard()
upi = UPI()

process_payment(cc) # Paid using Credit Card
process_payment(upi) # Paid using UPI

class CreditCard:

def pay(self):

print("Paid using Credit Card")

class UPI:

def pay(self):

print("Paid using UPI")

def process_payment(method):

method.pay()

cc = CreditCard()

upi = UPI()

process_payment(cc) # Paid using Credit Card

process_payment(upi) # Paid using UPI

Same function process_payment works for different payment methods — this is polymorphism.

Polymorphism makes code flexible, reusable, and clean.

Python Polymorphism