What is encapsulation in Python javatpoint?

What is encapsulation in Python javatpoint?

I apologize for the rules restriction earlier. Here's a detailed explanation of encapsulation in Python:

Encapsulation, a fundamental concept in object-oriented programming (OOP), is the practice of bundling data and methods that operate on that data within a single unit, such as a class or structure. In Python, encapsulation is achieved through the use of classes, where objects are instantiated from these classes.

Python's encapsulation mechanism allows developers to control access to an object's internal state (data) by providing a layer of abstraction around it. This is achieved through the use of access modifiers such as __init__, self, and private variables (variables preceded by double underscores, _).

When you create a class in Python, the constructor (__init__) is called automatically when an object is instantiated from that class. The __init__ method is responsible for initializing the object's internal state, which includes setting the values of instance variables.

Here's an example of encapsulation in Python:

class Person:
def init(self, name, age):
self._name = name  # private variable
self._age = age  # private variable
@property
def name(self):
return self._name
@name.setter
def name(self, value):
self._name = value
@property
def age(self):
return self._age
@age.setter
def age(self, value):
if value < 0:
raise ValueError("Age cannot be negative")
self._age = value
p = Person("John", 30)
print(p.name)  # John
print(p.age)   # 30
Attempting to modify the private variables directly will result in an AttributeError
try:
p._name = "Jane"
except AttributeError as e:
print(e)  # 'Person' object has no attribute '_name'
p.name = "Jane"  # allowed, because we've provided a setter method
print(p.name)     # Jane

In this example:

By encapsulating data and behavior within a class, you can:

In Python, encapsulation is achieved through the use of classes, properties, and access modifiers (like private variables). By controlling access to internal state and providing controlled interfaces for interaction, you can build robust, maintainable, and easy-to-understand software systems.

Python Encapsulation inheritance and polymorphism

Here's a detailed explanation of Python concepts: encapsulation, inheritance, and polymorphism:

Encapsulation

In object-oriented programming (OOP), encapsulation is the concept of bundling data and methods that operate on that data within a single unit, called a class or object. This helps to hide the implementation details from the outside world and provides a layer of abstraction.

In Python, encapsulation can be achieved by using classes and objects. A class is defined using the class keyword, and it has attributes (data) and methods (functions that operate on that data). The __init__() method is used to initialize the object's state when an instance is created.

For example:

class BankAccount:
def init(self, account_number, balance):
self.__account_number = account_number
self.__balance = balance
def get_balance(self):
return self.__balance
def deposit(self, amount):
self.__balance += amount
Create an instance of the class
account = BankAccount("123456", 1000)
print(account.get_balance())  # prints 1000
account.deposit(500)  # increases balance to 1500

In this example, the BankAccount class encapsulates the account number and balance. The get_balance() method allows access to the balance, while the deposit() method modifies the balance. The implementation details are hidden from the outside world.

Inheritance

Inheritance is a mechanism in OOP that allows one class to inherit the properties (methods and attributes) of another class. This helps to create a hierarchy of classes with shared behavior.

In Python, inheritance can be achieved using the class keyword with the (ParentClass) syntax:

class Animal:
def sound(self):
print(" generic animal sound")
class Dog(Animal):
def sound(self):
print("Woof!")
Create an instance of the Dog class
dog = Dog()
dog.sound()  # prints "Woof!"

In this example, the Dog class inherits from the Animal class and overrides the sound() method to provide its own implementation. The Dog class has access to all the methods and attributes defined in the Animal class.

Polymorphism

Polymorphism is a concept in OOP that allows objects of different classes to be treated as if they were of the same class. This can be achieved through method overriding or method overloading.

In Python, polymorphism can be achieved using function overloading (not available for built-in functions) or by creating abstract base classes and implementing them with concrete subclasses:

from abc import ABC, abstractmethod
class Shape(ABC):
@abstractmethod
def area(self):
pass
class Circle(Shape):
def init(self, radius):
self.radius = radius
def area(self):
return 3.14 * (self.radius ** 2)
class Rectangle(Shape):
def init(self, width, height):
self.width = width
self.height = height
def area(self):
return self.width * self.height
Create instances of different shapes and call the area method
circle = Circle(5)
rectangle = Rectangle(3, 4)
print(circle.area())  # prints 78.5
print(rectangle.area())  # prints 12

In this example, the Shape class is an abstract base class that defines the area() method. The Circle and Rectangle classes implement this interface with their own area() methods. When we call the area() method on different shapes, Python resolves the correct implementation based on the object's type.

In conclusion, encapsulation provides data hiding, inheritance allows for code reuse, and polymorphism enables objects of different classes to be treated as if they were of the same class. These concepts help developers create robust, maintainable, and reusable software systems in Python.