Lists

Store and manage multiple values in a single variable using Python lists.

Part of the free Python course at LearnCodingFast — hands-on lessons with examples you run in your browser, plus practice exercises and a quick quiz.

What You'll Learn in This Lesson

1. What Are Lists?

A list is a collection that stores multiple items in a single variable. Lists are ordered , changeable , and allow duplicate values .

Key Characteristics

• Ordered — Items have a defined order (index 0, 1, 2...)
• Mutable — You can add, remove, or change items
• Allow duplicates — Same value can appear multiple times
• Mixed types — Can hold strings, numbers, booleans, etc.

2. Creating Lists

Type

Example

Description

Empty list

my_list = []

Start with nothing

Strings

["a", "b", "c"]

List of text values

Numbers

[1, 2, 3, 4, 5]

List of integers

Mixed

[1, "hello", True]

Different types together

Nested

[[1, 2], [3, 4]]

Lists inside lists

3. Accessing Items by Index

Each item in a list has an index (position number). Python uses zero-based indexing — the first item is at index 0.

Code

Result

Explanation

fruits[0]

"apple"

First item

fruits[2]

"cherry"

Third item

fruits[-1]

"date"

Last item (negative index)

fruits[-2]

Second to last

4. Changing List Items

Lists are mutable — you can change items after creation by assigning a new value to a specific index.

5. Adding Items to Lists

Method

What It Does

.append(item)

Add item to the end

fruits.append("mango")

.insert(i, item)

Add item at position i

fruits.insert(1, "pear")

.extend(list)

Add all items from another list

fruits.extend(["kiwi", "lime"])

6. Removing Items from Lists

.remove(item)

Remove first match by value

fruits.remove("banana")

.pop()

Remove and return last item

last = fruits.pop()

.pop(i)

Remove and return item at index i

first = fruits.pop(0)

.clear()

Remove all items

fruits.clear()

del list[i]

Delete item at index i

del fruits[0]

7. List Slicing — Get a Range of Items

Slicing lets you get a portion of a list using the syntax list[start:end] .

Meaning

nums[1:4]

[1, 2, 3]

Index 1 to 3 (4 excluded)

nums[:3]

[0, 1, 2]

First 3 items

nums[3:]

[3, 4, 5]

From index 3 to end

nums[-2:]

[4, 5]

Last 2 items

nums[::2]

[0, 2, 4]

Every 2nd item

nums[::-1]

[5, 4, 3, 2, 1, 0]

Reversed list

8. Looping Through Lists

Use When

for item in list:

You just need the items

for fruit in fruits:

for i, item in enumerate(list):

You need index + item

for i, fruit in enumerate(fruits):

9. Useful List Methods

Method/Function

Returns

len(list)

Number of items

Integer

.sort()

Sort ascending (modifies list)

None

.sort(reverse=True)

Sort descending

.reverse()

Reverse the order

.count(x)

Count occurrences of x

.index(x)

Find position of x

.copy()

Create a copy

New list

sum(list)

Sum of numbers

Number

min(list) / max(list)

Smallest / largest value

Item

10. Checking if Item Exists

11. List Comprehension (Advanced)

List comprehension is a concise way to create lists in one line. It is more advanced but very powerful once you learn it.

12. Common Mistakes to Avoid

Mistake

Problem

Solution

Index out of range

list[10]

Check len(list) first

Forgetting 0-indexing

Expecting first item at 1

First item is at index 0

Removing nonexistent item

.remove("x")

Check if x in list: first

Aliasing instead of copying

list2 = list1

Use list2 = list1.copy()

Using parentheses

(1, 2, 3)

Use square brackets [1, 2, 3]

13. Practical Examples

Example 1: Shopping Cart

Example 2: Grade Calculator

Example 3: To-Do List

Summary: Quick Reference

Operation

Syntax

Create

[item1, item2]

fruits = ["apple", "banana"]

Access

list[index]

Change

list[i] = new

fruits[0] = "apricot"

Add

fruits.append("cherry")

Remove

Slice

list[start:end]

fruits[1:3]

Length

len(fruits)

Loop

Check exists

item in list

"apple" in fruits

Lesson 7 complete — you've unlocked Python's most-used data structure!

Lists are everywhere in Python — shopping carts, user records, game inventories, search results. You can now create, access, modify, slice, sort, and loop through them.

🚀 Up next: Dictionaries — store data with named keys instead of position numbers, perfect for structured records like user profiles.

Practice quiz

Continue this course

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• Next: Dictionaries