Python zip() built-in function

Examples

>>> furniture = ['table', 'chair', 'rack', 'shelf']
>>> price = [100, 50, 80, 40]
>>>
>>> for item, amount in zip(furniture, price):
...     print(f'The {item} costs ${amount}')
# The table costs $100
# The chair costs $50
# The rack costs $80
# The shelf costs $40

Other Usecases

The zip function in Python merges multiple iterables into tuples.

# Combining three lists
>>> list1 = [1, 2, 3]
>>> list2 = ['a', 'b', 'c']
>>> list3 = [True, False, True]

>>> zipped = zip(list1, list2, list3)
>>> print(list(zipped))
# Output: [(1, 'a', True), (2, 'b', False), (3, 'c', True)]

Unzipping

# Unzipping a zipped object
>>> zipped = [(1, 'a'), (2, 'b'), (3, 'c')]
>>> list1, list2 = zip(*zipped)
>>> print(list1)
# Output: (1, 2, 3)
>>> print(list2)
# Output: ('a', 'b', 'c')

More Examples

Zipping with Different Lengths

zip stops creating tuples when the shortest iterable is exhausted.

>>> numbers = [1, 2, 3]
>>> letters = ['a', 'b']
>>>
>>> for num, letter in zip(numbers, letters):
...     print(f'{num} -> {letter}')
# 1 -> a
# 2 -> b

Using zip with Dictionaries

You can use zip to combine keys and values from two lists into a dictionary.

>>> keys = ['name', 'age', 'city']
>>> values = ['Alice', 25, 'New York']
>>>
>>> my_dict = dict(zip(keys, values))
>>> print(my_dict)
# {'name': 'Alice', 'age': 25, 'city': 'New York'}

Using zip with List Comprehensions

You can use zip in list comprehensions for more concise code.

>>> list1 = [1, 2, 3]
>>> list2 = [4, 5, 6]
>>>
>>> summed = [x + y for x, y in zip(list1, list2)]
>>> print(summed)
# [5, 7, 9]