Iterating over lists

Walking a list properly

The plain for loop hands you each value directly:

for name in names:
    print(name)

When you need the position as well, enumerate() gives you both:

for index, name in enumerate(names):
    print(index, name)

That is much better than for i in range(len(names)): followed by names[i] — which works, but reads like a translation from another language.

To walk two lists together, zip() pairs them up and stops at the shorter one:

for name, score in zip(names, scores):
    print(name, score)

Your turn: write numbered(items) returning a list of strings like "1. apple", numbering from one.

Pairing lists with zip

zip() is the clean answer whenever two lists line up index for index.

Your turn: write totals(names, scores) returning a list of strings like "Ada: 90". Stop at the shorter list — zip does that for you.