List in Python [ English ]

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List in Python

1. Introduction

A list in Python is a collection of items stored in a single variable. It is one of the most versatile and widely used data structures.

Lists are:

• Ordered (elements have positions/indexes)
• Mutable (can be modified)
• Allow duplicate values
• Can store different data types

2. Creating a List

Syntax

list_name = [elements]

Examples

numbers = [1, 2, 3, 4]names = ["Amit", "Rahul", "Priya"]mixed = [10, "Python", 3.5]

3. Accessing Elements

Indexing (starts from 0)

numbers = [10, 20, 30] print(numbers[0])print(numbers[2])

Output

1030

Negative Indexing

print(numbers[-1])

Output

30

4. Slicing

numbers = [1, 2, 3, 4, 5] print(numbers[1:4])

Output

[2, 3, 4]

5. Modifying List Elements

numbers = [1, 2, 3] numbers[1] = 10print(numbers)

Output

[1, 10, 3]

6. Adding Elements

append() → adds at end

numbers = [1, 2]numbers.append(3)

insert() → adds at specific position

numbers.insert(1, 5)

extend() → adds multiple elements

numbers.extend([6, 7])

7. Removing Elements

remove() → removes specific value

numbers.remove(5)

pop() → removes last element

numbers.pop()

del → deletes element by index

del numbers[0]

8. List Operations

Concatenation

a = [1, 2]b = [3, 4] print(a + b)

Repetition

print([1, 2] * 2)

Membership

print(2 in [1, 2, 3])

9. Looping Through List

numbers = [1, 2, 3] for i in numbers: print(i)

10. Nested List

matrix = [[1, 2], [3, 4]] print(matrix[0][1])

Output

2

11. Important List Functions

12. Key Features

• Ordered collection
• Mutable (can change values)
• Allows duplicates
• Can store mixed data types

13. Summary

• Lists are used to store multiple items in one variable

• Created using square brackets []

• Support:

  • indexing
  • slicing
  • modification

• Provide many built-in methods for operations

• Very useful for data storage and manipulation