Explain the Python Classes and Objects with example

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Jk Malhotra · Answer

1. What is a Class?
A class is a blueprint for creating objects. It defines the structure (data) and behavior (functions) that the objects created from it will have.
Example:
class Dog:
    # class attribute (shared by all objects)
    species = "Canine"
    # constructor (called when creating an object)
    def __init__(self, name, age):
        self.name = name  # instance attribute
        self.age = age
    # instance method
    def bark(self):
        print(f"{self.name} says woof!")
2. What is an Object?
An object (also called an instance) is a real-world entity created from a class. Each object has its own unique data.
Example:
dog1 = Dog("Buddy", 3)
dog2 = Dog("Max", 5)
print(dog1.name)     # Buddy
print(dog2.age)      # 5
dog1.bark()          # Buddy says woof!
Each Dog object has its own name and age, but both share the same
species attribute.
3. Class vs Instance Attributes
Type
Definition
Example
Class Attribute
Shared by all instances
species = "Canine"
Instance Attribute
Unique to each object
self.name, self.age
Example:
Dog.species = "Dog"
print(dog1.species)  # Dog
Changing species in the class affects all dogs (unless overridden).
4. Methods in Classes
Instance methods → work with specific objects (self)Class methods → work with the class itself (cls)Static methods → general utility methods (don’t depend on either)
Example:
class Vehicle:
    count = 0  # class attribute
    def __init__(self, brand):
        self.brand = brand
        Vehicle.count += 1
    def show(self):
        print(f"This is a {self.brand}")
    @classmethod
    def total(cls):
        print(f"Total vehicles: {cls.count}")
    @staticmethod
    def is_motorcycle(wheels):
        return wheels == 2
Usage:
v1 = Vehicle("Toyota")
v2 = Vehicle("Honda")
v1.show()           # This is a Toyota
Vehicle.total()     # Total vehicles: 2
print(Vehicle.is_motorcycle(2))  # True
5. Special Methods (a.k.a. Magic or Dunder Methods)
Python classes can have “special” methods that start and end with double underscores.
Method
Purpose
__init__
Constructor (runs when creating object)
__str__
String representation (when using print())
__len__
Defines behavior for len(obj)
__add__
Defines behavior for obj1 + obj2
Example:
class Book:
    def __init__(self, title, pages):
        self.title = title
        self.pages = pages
    def __str__(self):
        return f"Book: {self.title}"
    def __len__(self):
        return self.pages
b = Book("Python 101", 300)
print(b)        # Book: Python 101
print(len(b))   # 300
6. Inheritance (OOP Concept)
A child class can inherit attributes and methods from a 
parent class.
Example:
class Animal:
    def speak(self):
        print("Some sound")
class Dog(Animal):
    def speak(self):  # overriding parent method
        print("Woof!")
dog = Dog()
dog.speak()  # Woof!

Method	Purpose
`__init__`	Constructor (runs when creating object)
`__str__`	String representation (when using `print()`)
`__len__`	Defines behavior for `len(obj)`
`__add__`	Defines behavior for `obj1 + obj2`

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Explain the Python Classes and Objects with example

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1 Answers

1. What is a Class?

2. What is an Object?

3. Class vs Instance Attributes

4. Methods in Classes

5. Special Methods (a.k.a. Magic or Dunder Methods)

6. Inheritance (OOP Concept)

Liked By

Type	Definition	Example
Class Attribute	Shared by all instances	`species = "Canine"`
Instance Attribute	Unique to each object	`self.name`, `self.age`