Lesson 9: Lists and Indexing

Topics Covered:

• What are lists and how to create them
• Accessing list items by index
• Modifying lists (adding/removing items)
• Looping through lists

What is a List?

A list is a collection of items stored in a specific order:

fruits = ["apple", "banana", "cherry"]

Accessing Items by Index

Indexing starts at 0, so the first item is at index 0:

print(fruits[0])  # apple
print(fruits[2])  # cherry

Changing Items in a List

fruits[1] = "blueberry"
print(fruits)  # ['apple', 'blueberry', 'cherry']

Adding Items

fruits.append("orange")
print(fruits)  # ['apple', 'blueberry', 'cherry', 'orange']

Removing Items

fruits.remove("apple")
print(fruits)  # ['blueberry', 'cherry', 'orange']

Length of a List

Use len() to find how many items are in a list:

print(len(fruits))  # 3

Looping Through a List

for fruit in fruits:
    print("I like", fruit)

Activity

• Create a list of your favorite games or movies.
• Print each item with a message.
• Add a new item and remove one.

games = ["Minecraft", "Mario", "Zelda"]

for game in games:
    print("I love playing", game)

games.append("Among Us")
games.remove("Mario")

print("Updated list:", games)