How is an abstract class implemented in Python?

In Python, abstract classes are implemented using the abc module (Abstract Base Classes). An abstract class is a class that is not intended to be instantiated directly but serves as a template for subclasses.

To create an abstract class:

1. Inherit the class from abc.ABC.
2. Use the @abstractmethod decorator for methods that must be implemented in subclasses.

Example:

from abc import ABC, abstractmethod

class Animal(ABC):
    @abstractmethod
    def make_sound(self):
        pass

class Dog(Animal):
    def make_sound(self):
        return "Bark"

class Cat(Animal):
    def make_sound(self):
        return "Meow"

# animal = Animal()  # Error: cannot instantiate an abstract class

dog = Dog()
print(dog.make_sound())  # Outputs: Bark

Thus, abstract classes help define an interface and ensure that subclasses implement the necessary methods.