Object oriented programming in python

Object-Oriented Programming (OOP) is a programming paradigm that allows you to structure your code using objects and classes. Python supports OOP, making it a powerful tool for creating scalable and reusable code. In this tutorial, we’ll introduce you to the basics of OOP in Python.

What Is a Class?

A class is a blueprint for creating objects. It defines the attributes and methods that the objects created from it will have. Here's how to define a simple class:

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def greet(self):
        print(f"Hello, my name is {self.name} and I am {self.age} years old.")

What Is an Object?

An object is an instance of a class. Here's how to create an object from the Person class:

person1 = Person("Alice", 30)
person1.greet()

Output:

Hello, my name is Alice and I am 30 years old.

Class Attributes vs Instance Attributes

Class attributes are shared across all instances, while instance attributes are unique to each instance. Here's an example:

class Circle:
    pi = 3.14  # Class attribute

    def __init__(self, radius):
        self.radius = radius  # Instance attribute

    def area(self):
        return Circle.pi * self.radius ** 2

circle1 = Circle(5)
print(circle1.area())

Output:

78.5

Inheritance

Inheritance allows you to create a class that inherits the attributes and methods of another class:

class Animal:
    def __init__(self, name):
        self.name = name

    def speak(self):
        print(f"{self.name} makes a sound.")

class Dog(Animal):
    def speak(self):
        print(f"{self.name} barks.")

dog = Dog("Buddy")
dog.speak()

Output:

Buddy barks.

Encapsulation

Encapsulation involves restricting access to certain attributes and methods using private and protected members:

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance  # Private attribute

    def deposit(self, amount):
        self.__balance += amount

    def get_balance(self):
        return self.__balance

account = BankAccount(1000)
account.deposit(500)
print(account.get_balance())

Output:

1500

Polymorphism

Polymorphism allows different classes to be treated as instances of the same class through a common interface:

class Cat(Animal):
    def speak(self):
        print(f"{self.name} meows.")

def animal_sound(animal):
    animal.speak()

cat = Cat("Whiskers")
animal_sound(cat)

Output:

Whiskers meows.

Next Steps

Practice creating your own classes and objects. Experiment with inheritance, encapsulation, and polymorphism to better understand OOP principles. Happy coding!