Python, How to zip unequal sized list, if one list 's length less than another, than fill None

Question

For example, I want to zip two different sized list:

list1=[1,2,3]
list2=[1,2,3,4]

# zip the two list will be [(1,1),(2,2),(3,3)]
zip(list1, list2)

What I want is:

[(1,1),(2,2),(3,3),(None,4)]

Is there any simple way to achieve this?

Does this answer your question? [Is there a zip-like function that pads to longest length in Python?](https://stackoverflow.com/questions/1277278/is-there-a-zip-like-function-that-pads-to-longest-length-in-python) — Phu Ngo, May 28 '20 at 04:09

score 3 · Answer 1 · edited May 28 '20 at 04:23

3

There is zip_longest in itertools which does that:

>>> from itertools import zip_longest
>>> list(zip_longest(range(1,4), range(1,5)))
[(1, 1), (2, 2), (3, 3), (None, 4)]

edited May 28 '20 at 04:23

A. Maman

answered May 28 '20 at 04:10

Aivar Paalberg

score 2 · Accepted Answer · answered May 28 '20 at 04:10

2

i think you want itertools.zip_longest

>>> list1=[1,2,3]
>>> list2=[1,2,3,4]
>>> import itertools
>>> list(itertools.zip_longest(list1, list2))
[(1, 1), (2, 2), (3, 3), (None, 4)]

answered May 28 '20 at 04:10

Dave Ankin

score 0 · Answer 3 · answered May 28 '20 at 04:13

0

This:

list1=[1,2,3]
list2=[1,2,3,4]

for _ in range(len(list2)-len(list1)): list1.append(None)

print(list(zip(list1, list2)))

Output:

[(1, 1), (2, 2), (3, 3), (None, 4)]

answered May 28 '20 at 04:13

Red

3 Answers3