Python enumerate & zip Examples

Short, runnable programs that show python enumerate() and zip() in action. Read the explanation, press Run, then change the code and try your own ideas. New to the topic? Start with the Python enumerate() and zip() lesson.

1Reporting positions with enumerate

When you need to say which item matched, enumerate gives you the position for free. With start=1 the day numbers read naturally.

Reporting positions with enumerate

temps = [18, 24, 31, 22, 35, 28]
for day, temp in enumerate(temps, start=1):
    if temp > 30:
        print(f"Day {day} was hot: {temp} degrees")

Expected outputDay 3 was hot: 31 degrees
Day 5 was hot: 35 degrees

2Three lists in step: a shopping bill

Item names, prices and quantities live in three lists that line up by position. One zip loop reads all three at once.

Three lists in step: a shopping bill

items = ["pen", "notebook", "stapler"]
prices = [1.5, 4.0, 7.25]
quantities = [10, 3, 2]
total = 0
for item, price, qty in zip(items, prices, quantities):
    line = price * qty
    total += line
    print(f"{item}: {qty} x {price} = {line}")
print("Total:", total)

Expected outputpen: 10 x 1.5 = 15.0
notebook: 3 x 4.0 = 12.0
stapler: 2 x 7.25 = 14.5
Total: 41.5

3A numbered leaderboard: enumerate around zip

zip makes the (player, points) pairs and enumerate puts a place number in front. The inner pair is unpacked with its own parentheses.

A numbered leaderboard: enumerate around zip

players = ["Mia", "Noah", "Zoe"]
points = [310, 275, 190]
for place, (player, pts) in enumerate(zip(players, points), start=1):
    print(f"#{place} {player}: {pts} points")

Expected output#1 Mia: 310 points
#2 Noah: 275 points
#3 Zoe: 190 points

4A lookup table from two lists

dict(zip(keys, values)) turns two parallel lists into a dictionary, so you can look a value up by its key instead of searching.

A lookup table from two lists

countries = ["France", "Japan", "Brazil"]
capitals = ["Paris", "Tokyo", "Brasilia"]
capital_of = dict(zip(countries, capitals))
print(capital_of)
print("Capital of Japan:", capital_of["Japan"])

Expected output{'France': 'Paris', 'Japan': 'Tokyo', 'Brazil': 'Brasilia'}
Capital of Japan: Tokyo

5Uneven lists: zip versus zip(strict=True)

Plain zip quietly stops at the shortest list. With strict=True the mismatch raises a ValueError. The try/except part (covered in a later lesson) only lets the program print the error message instead of stopping.

Uneven lists: zip versus zip(strict=True)

names = ["Asha", "Ben", "Chen"]
scores = [88, 92]
print(list(zip(names, scores)))
try:
    for name, score in zip(names, scores, strict=True):
        print(name, score)
except ValueError as error:
    print("Caught:", error)

Expected output[('Asha', 88), ('Ben', 92)]
Asha 88
Ben 92
Caught: zip() argument 2 is shorter than argument 1

6Comparing neighbours with zip(items, items[1:])

Zipping a list with a copy of itself shifted by one gives you each value next to the one after it. It stops after the last pair, so there is no index to run off the end.

Comparing neighbours with zip(items, items[1:])

prices = [100, 104, 103, 110, 108]
for today, tomorrow in zip(prices, prices[1:]):
    change = tomorrow - today
    print(f"{today} -> {tomorrow}: {change:+}")

Expected output100 -> 104: +4
104 -> 103: -1
103 -> 110: +7
110 -> 108: -2

Practise next

Python enumerate() and zip() exercises → Back to the lesson

Python for Loops examples Python range() Function examples Python Dictionaries examples Python List Comprehensions examples