Python Mastery – From Basics to Brilliance / Python Fundamentals

Mutable and Immutable Objects

🔄 Mutable and Immutable Objects

In Python, objects are either mutable or immutable depending on whether their contents can be changed after they are created.

🟢 Mutable Objects

Mutable objects can be changed after creation.

Common mutable types:

list
set
dictionary

Example:

numbers = [1, 2, 3]

numbers[0] = 10

print(numbers) # [10, 2, 3]

The same list was changed.

🔴 Immutable Objects

Immutable objects cannot be changed after creation.

Common immutable types:

int
float
bool
str
tuple

Example:

x = 10

x = 20

Here, the original 10 is not changed. Instead, x is made to refer to a new integer object containing 20.

Strings work similarly:

name = "Python"

name[0] = "J"   # ❌ Error

A string cannot be modified directly.

⚖️ Mutable vs Immutable

Mutable 🟢

Immutable 🔴

Can be changed after creation

Cannot be changed after creation

list

int

set

float

dict

bool

str

tuple