Encapsulation is a principle of object-oriented programming that promotes the bundling of data and methods within a class. It hides the internal details and provides a public interface for interacting with the object. Access modifiers are used to control the visibility and accessibility of class members (attributes and methods) from outside the class.

Let’s explore encapsulation and access modifiers in Python:

# Encapsulation and access modifiers
class Car:
    def __init__(self, brand, model, year):
        self._brand = brand  # Protected attribute
        self.__model = model  # Private attribute
        self.year = year  # Public attribute

    def __display_private(self):
        print("Private method.")

    def display_public(self):
        print("Public method.")
        self.__display_private()

# Creating object
car = Car("Toyota", "Camry", 2020)

# Accessing attributes (protected and public)
print("Brand:", car._brand)
print("Year:", car.year)

# Calling methods (public)
car.display_public()

Explanation:

• We define a class Car with attributes _brand (protected), __model (private), and year (public).
• The _brand attribute is considered protected, indicating that it should not be accessed directly from outside the class. However, it can still be accessed, although it is conventionally treated as private.
• The __model attribute is marked as private, meaning it should not be accessed or modified from outside the class.
• We define a private method __display_private() that is meant to be used internally within the class.
• We define a public method display_public() that can be accessed from outside the class. It also calls the private method.

Now it’s time for a practical task:

Task 13:

Refactor the Rectangle class (from a previous lesson) to encapsulate the width and height attributes by marking them as private. Create getter and setter methods (get_width(), get_height(), set_width(), set_height()) to access and modify the attributes. Test the getter and setter methods by creating a Rectangle object, setting its width and height, and retrieving their values.

Once you’ve completed the task, you can proceed to the next lesson.