How to create a list of dictionaries from a dictionary with lists of different lengths

Question

I want to create a list of dictionaries with the same index element from each list.

I have this dictionary:

d = {'name': ['bob', 'john', 'harry', 'mary'],       'age': [13, 19, 23],       'height': [164, 188],       'job': ['programmer']} 

The desired output is:

d2 = [{'name': 'bob', 'age': 13, 'height': 164, 'job': 'programmer'},        {'name': 'john', 'age': 19, 'height': 188},        {'name': 'harry', 'age': 23},       {'name': 'mary'}] 

I have tried something like this:

d2 = [dict(zip(d, t)) for t in zip(*d.values())] 

But my output is:

d2 = [{'name': 'bob', 'age': 13, 'height': 164, 'job': 'programmer'}] 

I think this is happening because the lists have different lengths.

Answer 1

You can use itertools.zip_longest and filter out None values:

from itertools import zip_longest  [{x: y for x, y in zip(d, t) if y is not None} for t in zip_longest(*d.values())] # [{'name': 'bob', 'age': 13, 'height': 164, 'job': 'programmer'},  #  {'name': 'john', 'age': 19, 'height': 188},  #  {'name': 'harry', 'age': 23},  #  {'name': 'mary'}] 

Answer 2

You can use zip_longest here:

from itertools import zip_longest  keys = d.keys()  d2 = [     {k: v for k, v in zip(keys, vs) if v is not None}     for vs in zip_longest(*d.values()) ]

If the values can be None as well, we can circumvent that by using a dummy value:

from itertools import zip_longest  keys = d.keys() dummy = object()  d2 = [     {k: v for k, v in zip(keys, vs) if v is not dummy}     for vs in zip_longest(*d.values(), fillvalue=dummy) ]

Here the dummy is an object which we are sure that is not part of the items in d (since we construct it after we constructed d). By using an is comparison, we thus can know if that value was the "fillvalue".

This will give us:

>>> d2 [{'name': 'bob', 'age': 13, 'height': 164, 'job': 'programmer'}, {'name': 'john', 'age': 19, 'height': 188}, {'name': 'harry', 'age': 23}, {'name': 'mary'}]