Python challenge_17

Custom zip

• The built-in zip function "zips" two lists.

• Write your own implementation of this function.

• Define a function named zap.

• The function takes two parameters, a and b, These are lists.

• Your function should return a list of tuples.

• Each tuple should contain one item from the a list and one from b.

• You may assume a and b have equal lengths.

• If you don't get it, think of a zipper.

For example:

zap(
    [0, 1, 2, 3],
    [5, 6, 7, 8]
)

Should return:

[
    (0, 5),
    (1, 6),
    (2, 7),
    (3, 8)
]

Hint

• Use a while loop or a for loop with range to count up an index i.
• Then use i to access each element in a and b at a time.
• Create a tuple and append it to a result list that you gradually build up.

My solution

def zap(a, b):
    zap_list = []
    for i in range(len(a)): 
        zap_list.append((a[i], b[i]))
    return zap_list

print(zap([0, 1, 2, 3], [5, 6, 7, 8]))

Another solution

def zap(a, b):
    result = []
    for i in range(len(a)):
        item_from_a = a[i]
        item_from_b = b[i]
        tup = (item_from_a, item_from_b)
        result.append(tup)
    return result

concise solution with list comprehensions

def zap(a, b):
    return [(a[i], b[i]) for i in range(len(a))]

All the best to you.

Comments

[Sivaranjan Goswami]

This is wrong. Zip supports any number of lists to be zipped. Each list should have the same length. Here is the correct implementation: