Day 02: Getting Started with OOP in Python – Classes & Objects

Today I began my journey into Object Oriented Programming (OOP) in Python. OOP is a programming paradigm based on the concept of "objects", which can contain data and code — data in the form of attributes, and code in the form of methods.

1. Class

A class is like a blueprint for creating objects.

class Student:
    pass

2. Object

An object is an instance of a class.

c1 = Student()
print(type(c1))

3. Constructor (__init__)

This special method is called when an object is created.

class Student():
    def __init__(self,name,marks):
        self.name = name
        self.marks = marks

s1 = Student("Mr stark",89)
print(s1.name)

4. Instance Variables & Methods

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

    def greet(self):
    print(f"Hello, I’m {self.name}!")

h1 = Hello("Ironman")
print(h1.greet())

5. Class & Instance Attribute

class Students:
    college_name = "ABC"
    name = "Anonymous"

    def __init__(self,name,marks):
        self.name = name
        self.marks = marks
        print("Adding new sutdent in Database")

s1 = Students("Karan", 97)
print(s1.name)
print(s1.college_name)

In the above code snippet college_name is a class Attribute that is defined for all the objects that we are creating and is valid for all like we are doing s1.college_name which gives us “ABC”