Class in Python

 Class is an important topic in Object-Oriented Programming (OOP).

A class is like a blueprint. It is used to create objects.

What is a Class?

A class is created using the class keyword.

class Student:
    name = "Sathwik"

student1 = Student()

print(student1.name)

Output:

Sathwik

Here, student is the class and student1 is the object.

What is an Object?

An object is created from a class.

An object is an instance of class.

class Student:
    name = "Sathwik"

student1 = Student()

print(student1.name)

Here:

• student → Class
• student1→ Object
• name → Attribute

We can create multiple objects from the same class.

Class with  __init__()

The __init__() method is used to initialize object data.

class Student:

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

student1 = Student("Sathwik", 21)

print(student1.name)
print(student1.age)

Output:

Sathwik
21

The self keyword refers to the current object.

Class with a Method

A function inside a class is called a method.

class Student:

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

    def greet(self):
        print("Hello", self.name)

student1 = Student("Sathwik")

student1.greet()

Output:

Hello Sathwik

Multiple Objects

One class can be used to create many objects.

class Student:

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

student1 = Student("Sathwik")
student2 = Student("Rahul")

print(student1.name)
print(student2.name)

Output:

Sathwik
Rahul

Class Attribute

A variable created directly inside a class is called a class attribute.

class Student:
    college = "ABC College"

student1 = Student()

print(student1.college)

Output:

ABC College

Instance Attribute

Variable unique to each individual object

A variable created using self is called an instance attribute.

class Student:

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

student1 = Student("Sathwik")

print(student1.name)

Here, name belongs to the particular object student1.