Three lists zipped into list of dicts

Question

Consider the following:

>>> # list of length n
>>> idx = ['a', 'b', 'c', 'd']

>>> # list of length n
>>> l_1 = [1, 2, 3, 4]

>>> # list of length n
>>> l_2 = [5, 6, 7, 8]

>>> # first key
>>> key_1 = 'mkt_o'

>>> # second key
>>> key_2 = 'mkt_c'

How do I zip this mess to look like this?

{
    'a': {'mkt_o': 1, 'mkt_c': 5},
    'b': {'mkt_o': 2, 'mkt_c': 6},
    'c': {'mkt_o': 3, 'mkt_c': 6},
    'd': {'mkt_o': 4, 'mkt_c': 7},
    ...
}

The closest I've got is something like this:

>>> dict(zip(idx, zip(l_1, l_2)))
{'a': (1, 5), 'b': (2, 6), 'c': (3, 7), 'd': (4, 8)}

Which of course has tuples as values instead of dictionaries, and

>>> dict(zip(('mkt_o', 'mkt_c'), (1,2)))
{'mkt_o': 1, 'mkt_c': 2}

Which seems like it might be promising, but again, fails to meet requirements.

Answer 1

{k : {key_1 : v1, key_2 : v2} for k,v1,v2 in zip(idx, l_1, l_2)}

Answer 2

Solution 1: You may use zip twice (actually thrice) with dictionary comprehension to achieve this as:

idx = ['a', 'b', 'c', 'd']
l_1 = [1, 2, 3, 4]
l_2 = [5, 6, 7, 8]

keys = ['mkt_o', 'mkt_c']   # yours keys in another list

new_dict = {k: dict(zip(keys, v)) for k, v in zip(idx, zip(l_1, l_2))}

Solution 2: You may also use zip with nested list comprehension as:

new_dict = dict(zip(idx, [{key_1: i, key_2: j} for i, j in zip(l_1, l_2)]))

Solution 3: using dictionary comprehension on top of zip as shared in DYZ's answer:

new_dict = {k : {key_1 : v1, key_2 : v2} for k,v1,v2 in zip(idx, l_1, l_2)}

All the above solutions will return new_dict as:

{
     'a': {'mkt_o': 1, 'mkt_c': 5}, 
     'b': {'mkt_o': 2, 'mkt_c': 6}, 
     'c': {'mkt_o': 3, 'mkt_c': 7},
     'd': {'mkt_o': 4, 'mkt_c': 8}
 }