Abstract Classes

Abstract classes are classes that cannot be instantiated directly. They serve as base classes for other classes, defining a common interface that subclasses must implement.

Creating Abstract Classes:

To create an abstract class in Python, you use the abc module and the @abstractmethod decorator:

Python

from abc import ABC, abstractmethod

class Animal(ABC):

  @abstractmethod

  def make_sound(self):

    pass

Key Points:

• Abstract classes are defined using the ABC class from the abc module.

• The @abstractmethod decorator marks methods as abstract.

• Abstract methods must be implemented in subclasses.

• You cannot create instances of abstract classes directly.

Example:

Python

class Dog(Animal):

  def make_sound(self):

    print("Woof!")

class Cat(Animal):

  def make_sound(self):

    print("Meow!")

# Trying to create an instance of the abstract class will raise an error:

# animal = Animal()  # TypeError: Can't instantiate abstract class Animal with abstract method make_sound

Benefits of Abstract Classes:

• Enforce common interface: Ensure that subclasses implement required methods.

• Promote code reusability: Provide a base class for derived classes.

• Improve code organization: Define a clear structure for related classes.

Cautions:

• Abstract classes cannot be instantiated directly.

• All abstract methods must be implemented in subclasses.

• Overusing abstract classes can make code more complex.

By understanding abstract classes, you can create more structured and maintainable object-oriented programs in Python.