What is polymorphism in the context of programming?

Polymorphism is a concept that allows working with objects of different classes through a common interface. In Python, this is mainly implemented through "duck typing" and inheritance.

Duck Typing:

If an object can perform the required operations (it has the necessary methods and attributes), then its specific type does not matter.

# Example of duck typing
class Dog:
    def speak(self):
        return "Woof!"

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

def make_sound(animal):
    return animal.speak()

# Although Dog and Cat are different classes, make_sound works with both
dog = Dog()
cat = Cat()

print(make_sound(dog))
print(make_sound(cat))

Polymorphism through inheritance:

Subclasses can override methods of the parent class, providing their specific implementation.

# Example of polymorphism through inheritance
class Animal:
    def speak(self):
        raise NotImplementedError("Subclasses must implement this method")

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

class Cat(Animal):
    def speak(self):
        return "Meow!"

def make_sound(animal):
    return animal.speak()

# Objects of different subclasses call their own version of speak()
dog = Dog()
cat = Cat()

print(make_sound(dog))
print(make_sound(cat))

Advantages:

• Simplifies code, making it more flexible and readable.
• Allows working with collections of heterogeneous objects uniformly.
• Facilitates system extension with new types without modifying existing code.

Examples in Python's standard library:

• Built-in functions like len(), iter(), str() work with different data types.
• Operators (e.g., + for addition of numbers, string concatenation, list merging).