How to make zip_longest available in itertools using Python 2.7

Question

When trying to import this function on a Python Jupyter 2.7 nb running on Windows 10, I get this error:

I believe I hadn't encountered problems in the past because I was using Python 3. So I wonder if it is just that it is not available in Python 2, or if there is a way of making it work.

score 34 · Accepted Answer · answered Jun 10 '17 at 21:13

34

For Python 3, the method is zip_longest:

from itertools import zip_longest

For Python 2, the method is izip_longest:

from itertools import izip_longest

answered Jun 10 '17 at 21:13

Ajax1234

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Points for now - will accept when it allows me to (6 min). Ty – Antoni Parellada Jun 10 '17 at 21:19
Glad I could help! – Ajax1234 Jun 10 '17 at 21:21
1

Don't forget in Python 3, map and zip functions return iterators instead of lists, so you want to list() them if you are expecting a list. I am constantly burned by this. I hate it. But lazy evaluation is king. – RufusVS Nov 15 '18 at 15:42

Alireza Afzal Aghaei · Answer 2 · 2019-06-25T19:41:01.123

9

If you don't know which version of python runs the script you can use this trick:

try:
    from itertools import zip_longest
except ImportError:
    from itertools import izip_longest as zip_longest

# now this works in both python 2 and 3
print(list(zip_longest([1,2,3],[4,5])))

edited Jun 25 '19 at 19:41

answered Jun 11 '17 at 06:28

Alireza Afzal Aghaei

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How to make zip_longest available in itertools using Python 2.7

2 Answers2