merge two lists into dictionary

Question

I'm trying to merge two lists to dict:

l1 = [1, 3, 6, 0, 1, 1]
l2 = ['foo1', 'foo2', 'foo1', 'foo2', 'foo2', 'bar1']

I'd like to get:

list = [{"foo1": 1},
             {"foo2": 3},
             {"foo1": 6},
             {"foo2": 0},
             {"foo2": 1},
             {"bar1": 1},]

trying to use zip but get an error :"<zip object at 0x000>"

Well, It's not an error, It's just a string representation of zip object, — Abdul Niyas P M, Jan 05 '21 at 03:19
`[{l2_item:l1_item} for l1_item,l2_item in zip(l1,l2)]` does this produce what you want? — Ted Brownlow, Jan 05 '21 at 03:22
duplicate of https://stackoverflow.com/questions/7271385/how-do-i-combine-two-lists-into-a-dictionary-in-python and https://stackoverflow.com/questions/209840/how-do-i-convert-two-lists-into-a-dictionary — Biarys, Jan 05 '21 at 03:25
Does this answer your question? [How do I convert two lists into a dictionary?](https://stackoverflow.com/questions/209840/how-do-i-convert-two-lists-into-a-dictionary) — Biarys, Jan 05 '21 at 03:26

score 4 · Accepted Answer · answered Jan 05 '21 at 03:23

You can try this:

l1 = [1, 3, 6, 0, 1, 1]
l2 = ['foo1', 'foo2', 'foo1', 'foo2', 'foo2', 'bar1']

data = [{k: v} for k, v in zip(l2, l1)]

print(data)

Output:

[{'foo1': 1}, {'foo2': 3}, {'foo1': 6}, {'foo2': 0}, {'foo2': 1}, {'bar1': 1}]

I wouldn't consider this an ideal data structure though, unless you have a lot more data in the individual dictionaries.

score 2 · Answer 2 · answered Jan 05 '21 at 03:42

The answer by @Tenacious B achieves what you requested.

You might, however, be better with a dictionary of lists. The keys would be items from l2 and values would be a list containing the corresponding values from l1. A collections.defaultdict makes this easy:

l1 = [1, 3, 6, 0, 1, 1]
l2 = ['foo1', 'foo2', 'foo1', 'foo2', 'foo2', 'bar1']

from collections import defaultdict

d = defaultdict(list)
for k, v in zip(l2, l1):
    d[k].append(v)

print(d)

Output:

defaultdict(, {'foo1': [1, 6], 'foo2': [3, 0, 1], 'bar1': [1]})

Now you can access the data by key:

>>> d['foo2']
[3, 0, 1]
>>> d['foo1']
[1, 6]

score 1 · Answer 3 · answered Jan 05 '21 at 03:20

1

I'm pretty sure <zip object at 0x0000021A9C9F71C0> is not an error, you just haven't execute the code yet. It is stored in a zip object which is waiting for execution.

answered Jan 05 '21 at 03:20

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merge two lists into dictionary

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