Introduction:
Abstraction is an important concept in object-oriented programming that allows you to hide the internal details of a class and expose only the relevant information to the outside world. In Python, abstraction is achieved using abstract classes and abstract methods.

In this tutorial, we will explore abstraction in Python classes and provide examples to illustrate its usage.

Prerequisites:

Before diving into abstraction, you should have a basic understanding of object-oriented programming (OOP) concepts, such as classes, objects, and inheritance in Python.

1. Abstract Classes: An abstract class is a class that cannot be instantiated. It is meant to be subclassed and provides a blueprint for other classes. In Python, abstraction is achieved using the built-in abc module, which stands for “Abstract Base Classes.”

To create an abstract class, you need to import the ABC class and decorate the abstract class with the @abstractmethod decorator. This decorator is used to indicate that a method is abstract and must be implemented by any concrete subclasses.

Example:

from abc import ABC, abstractmethod

class Animal(ABC):

    @abstractmethod
    def make_sound(self):
        pass

    @abstractmethod
    def eat(self):
        pass

class Dog(Animal):

    def make_sound(self):
        print("Woof!")

    def eat(self):
        print("The dog is eating.")

In this example, we define an abstract class called Animal, which has two abstract methods: make_sound() and eat(). These methods are decorated with the @abstractmethod decorator, indicating that any concrete subclass must implement them. The Dog class is a concrete subclass of Animal and provides implementations for the abstract methods.

2. Abstract Methods: Abstract methods are methods that are declared in an abstract class but have no implementation. They serve as placeholders for methods that must be implemented by the concrete subclasses.

Example:

from abc import ABC, abstractmethod

class Shape(ABC):

    @abstractmethod
    def area(self):
        pass

    @abstractmethod
    def perimeter(self):
        pass

class Rectangle(Shape):

    def __init__(self, length, width):
        self.length = length
        self.width = width

    def area(self):
        return self.length * self.width

    def perimeter(self):
        return 2 * (self.length + self.width)

In this example, we define an abstract class called Shape, which has two abstract methods: area() and perimeter(). The Rectangle class is a concrete subclass of Shape and provides implementations for these methods.

3. Using Abstraction: Abstraction allows you to create a hierarchy of classes where the abstract base class defines the common interface, and the concrete subclasses provide their own implementations. By doing so, you can enforce certain behaviors across different classes while allowing flexibility in the implementation details.

from abc import ABC, abstractmethod

class Vehicle(ABC):

    @abstractmethod
    def start(self):
        pass

    @abstractmethod
    def stop(self):
        pass

class Car(Vehicle):

    def start(self):
        print("Car started.")

    def stop(self):
        print("Car stopped.")

class Motorcycle(Vehicle):

    def start(self):
        print("Motorcycle started.")

    def stop(self):
        print("Motorcycle stopped.")

In this example, we define an abstract class called Vehicle, which has two abstract methods: start() and stop(). The Car and Motorcycle classes are concrete subclasses of Vehicle and provide their own implementations for these methods.

4. Benefits of Abstraction:

• Abstraction allows you to create a clear separation between the interface and the implementation of a class. Users of the class only need to know about the interface (abstract methods) without worrying about the implementation details.
• Abstraction promotes code reusability and modularity. By defining abstract classes with common interfaces, you can easily create new classes that adhere to the same interface, making it easier to maintain and extend your codebase.
• Abstraction helps in enforcing a contract among different classes. By defining abstract methods, you can ensure that certain behaviors or operations are implemented consistently across different subclasses.

Conclusion: Abstraction is a powerful concept in object-oriented programming that allows you to hide implementation details and provide a clean interface for interacting with your classes. In Python, you can achieve abstraction using abstract classes and abstract methods. By leveraging abstraction, you can create more modular, reusable, and maintainable code.