What Is a List, Really? · Data Structures & Algorithms

Ch 2 · Arrays & Lists — The Workhorse — card 1 of 3.

A Python list is an array: a row of numbered boxes sitting next to each other in memory. Because they are numbered (starting at 0), the computer can jump straight to any box by its index — no searching required.

scores = [90, 85, 100, 70]

print(scores[0])     # first box  -> 90    (O(1))
print(scores[2])     # third box  -> 100   (O(1))
print(len(scores))   # how many   -> 4