Python Lists

Lists store multiple values in one variable. They are ordered, and they are mutable (you can change them).

Lists are used everywhere:

• storing names
• storing items in a cart
• storing results from a database
• storing rows in a CSV file

Create a list

cities = ["Miami", "Austin", "Denver"]
print(cities)

Expected output:

['Miami', 'Austin', 'Denver']

Indexing (get items)

cities = ["Miami", "Austin", "Denver"]

print(cities[0])
print(cities[1])
print(cities[-1])

Expected output:

Miami
Austin
Denver

Slicing (get part of list)

numbers = [10, 20, 30, 40, 50]
print(numbers[1:4])

Expected output:

[20, 30, 40]

Updating a list

fruits = ["apple", "banana"]

fruits.append("orange")
print(fruits)

fruits.remove("banana")
print(fruits)

fruits[0] = "grape"
print(fruits)

Expected output:

['apple', 'banana', 'orange']
['apple', 'orange']
['grape', 'orange']

Sorting (and why it matters)

numbers = [3, 1, 4, 1, 5]
numbers.sort()
print(numbers)

Expected output:

[1, 1, 3, 4, 5]

Graph: list operations

flowchart LR
  A[List] --> B[Index access]
  A --> C[Slicing]
  A --> D[append/remove]
  A --> E[sort]

In the next lesson, you will learn if statements, how conditions work, and how to build decision logic correctly.