Polymorphism Definition

Polymorphism means same function name, different behaviors, depending on class or input.

Two types in Python:

Type	Meaning
Compile-time (Overloading)	Same function, different parameters (simulated in Python)
Runtime (Overriding)	Child class modifies parent method

Method Overriding (Runtime Polymorphism)

class Animal:
    def speak(self):
        print("Animal speaks")

class Dog(Animal):
    def speak(self):
        print("Dog barks")

class Cat(Animal):
    def speak(self):
        print("Cat meows")

for pet in [Dog(), Cat()]:
    pet.speak()

Each object responds differently to the same speak() call.

Method Overloading (Simulated)

class Math:
    def add(self, a, b, c=None):
        if c:
            return a + b + c
        return a + b

m = Math()
print(m.add(1, 2))
print(m.add(1, 2, 3))

Python doesn’t support true overloading, so we use default parameters.

Polymorphism with Functions & Objects

class Car:
    def move(self):
        print("Car is driving")

class Plane:
    def move(self):
        print("Plane is flying")

def operate(vehicle):
    vehicle.move()

operate(Car())
operate(Plane())

Same function → different behavior based on object type.

Polymorphism with Inheritance

class Shape:
    def area(self):
        raise NotImplementedError("Subclass must implement this")

class Square(Shape):
    def __init__(self, side):
        self.side = side
    def area(self):
        return self.side * self.side

class Circle(Shape):
    def __init__(self, r):
        self.r = r
    def area(self):
        return 3.14 * self.r * self.r

for s in [Square(4), Circle(5)]:
    print(s.area())

Child classes provide unique logic for inherited structure.

Real-World Example (Combined)

class User:
    def login(self):
        print("Login from User")

class Admin(User):
    def login(self):
        print("Admin login with security check")

class Customer(User):
    def login(self):
        print("Customer login")

users = [Admin(), Customer(), User()]
for u in users:
    u.login()

Explanation

Admin & Customer override the login() method.
Same method name → different behaviors based on object type.

Summary

Feature	What It Does	Example
Inheritance	Reuse parent class features	`class B(A)`
Multiple Inheritance	Child from multiple parents	`class C(A,B)`
Polymorphism	Same method, different behavior	Overriding
Overriding	Modify parent method	Redefine in child
Overloading	Same name, different arguments	Default parameters

Python Polymorphism