Python Lists
3 min read ·
Lists are one of the most important and widely used data structures in Python.
They allow you to store multiple values in a single variable, and they are ordered, mutable, and flexible.
Lists are used everywhere—from basic programs to real-world applications.
What Is a List?
A list is a collection that:
- Is ordered
- Is mutable (can be changed)
- Allows duplicate values
- Can store different data types
Creating a List
Using Square Brackets
Using list() Constructor
Access List Items (Indexing)
List items are indexed starting from
0.Change List Items (Mutable Nature)
List Length
Check Item Exists
Loop Through a List
Add Items to a List
append() – Add at the End
insert() – Add at Specific Index
Remove Items from a List
remove() – Remove by Value
pop() – Remove by Index
del Keyword
List Slicing
Copy a List (Important)
Wrong Way (Reference Copy)
Correct Way (Actual Copy)
Sort a List
Reverse a List
List Methods (Quick Overview)
| Method | Description |
|---|---|
append() | Add item |
insert() | Insert at index |
remove() | Remove value |
pop() | Remove index |
sort() | Sort list |
reverse() | Reverse list |
copy() | Copy list |
clear() | Remove all items |
count() | Count occurrences |
index() | Find index |
List with Mixed Data Types
Common Mistakes
Modifying List While Iterating
Practice
- Create a list of numbers and modify it
- Add and remove elements
- Copy a list safely
- Sort and reverse a list