A class in Python is a user-defined template for creating objects. It is a collection data and functions together, making it easier to manage and use them. When we create a new class, we define a new type of object. We can then create multiple instances of this object type.

Syntax:

class CLASS_NAME:
    variables
    
    def FUNCTION_NAME:
        return()

OBJECT_NAME = CLASS_NAME()

#Get class variables
print(OBJECT_NAME.variables)

#use functions of a class
OBJECT_NAME.FUNCTION_NAME()

Example

class test:
    a = 10
    b = "hello"
    c = [10,20,30]
        
    def add(self,x,y):
      return(x+y)
                
t1 = test()

print(t1.a,t1.b,t1.c)

z = t1.add(10,30)
print(z)

Special init() function in class

In Python, class has init() function. It automatically executes when an object is created. This function does not have a return() functionality

class CLASS_NAME:
    def __init__(self):
      print("executes automatically")

OBJECT_NAME = CLASS_NAME()

init() example

class Dog:
    species = "Dogs"  # Class attribute

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

# Creating an object of the Dog class
dog1 = Dog("Buddy", 3)
dog2 = Dog("Tom", 5)

print(dog1.name,dog1.age)
print(dog1.species)

print(dog2.name,dog2.age)
print(dog2.species)

Practise Programs

1. Create a class that has 3 variables of int, string, float and create a object and print all the variables in the class object
2. Create a class that has functions to has add two numbers,subtract two numbers,multiply three number and a function for simple interest. then create a class object and call all the functions with right arguments and print them

Class usage in real world senarios

The real power of class comes from OOPs. OOPs empowers Python with modularity, reusability and easy to maintain code. Sample code of Both the below files have to be in the same folder for the code to work

• dataGather.py has the class assigned in it
• telangana_data.py python file: has the program that imports the class from dataGather.py
• after you copy the files execute telangana_data.py

dataGather.py

class data:
    # Class attribute
    nationality = "Indian"

    def __init__(self, name, state, gender,date_of_birth):
        # Instance attribute
        self.name = name  
        self.state = state
        self.gender = gender
        self.date_of_birth = date_of_birth #list example [16,01,2000] 16-01-2000

    def age(self,year):
        a = year - self.date_of_birth[2]
        return(a)

telangana_data.py

import dataGather

# present year
current_year = 2025

h1 = dataGather.data("Ram","Telangana","Male",[10,5,1999])
h2 = dataGather.data("Sita","Telangana","Female",[10,6,2000])

print(h1.name,"age is",h1.age(current_year))
print(h2.name,"age is",h2.age(current_year))

Advance practise programs

Classes and programs have to be in different files

1. Create a class that has 3 variables int.string.float and create a object and print all the variables in the class object
2. Create a class that functions to has add two numbers,subtract two numbers,multiply three number and a function for simple interest. then create a class object and call all the functions with right arguments and print them