Multikey dictionary from 2d array

Question

Trying to create multikey dictionary with values from the list, where keys of the dictionary are first column and first row values, except the empty cells.

The code below doesn't return the expected result. I also tried with map function and list comprehension.

# list data
list_data = [['', '', 'VARIANT1', 'VARIANT2'],
         ['power', 'kW', '12', '20'],
         ['range', 'm', '200', '400'],
         ['colour', '', 'blue', 'yellow']]

# my code
import collections
dict_data = collections.defaultdict()
for row in range(1: len(list_data)):
    for column in range(2: len(list_data[0])):
        dict_data[(list_data[row][0], list_data[0][column])
              ] = list_data[row][column]

# desired output
dict_data = {('power', 'VARIANT1'): '12',
         ('range', 'VARIANT1'): '200',
         ('colour', 'VARIANT1'): 'blue',
         ('power', 'VARIANT2'): '20',
         ('range', 'VARIANT2'): '400',
         ('colour', 'VARIANT2'): 'yellow', }

This is a syntax error `list_data = [[, , 'VARIANT1', 'VARIANT2']` is that a typo? — Mark, Apr 08 '19 at 22:15
There are actually 3 of those syntax errors within `list_data`... — Reedinationer, Apr 08 '19 at 22:22

score 0 · Answer 1 · answered Nov 21 '19 at 11:54

You can do this with a dictionary comprehension:

list_data = [['', '', 'VARIANT1', 'VARIANT2'],
         ['power', 'kW', '12', '20'],
         ['range', 'm', '200', '400'],
         ['colour','' , 'blue', 'yellow']]


keys = {(x[0], y): x[i]  for x in list_data[1:] for i, y in enumerate(list_data[0]) if i >= 2}

keys_sorted = {k: v for k, v in sorted(keys.items(), key=lambda x: x[0][1])}

Output:

>>> keys
{('power', 'VARIANT1'): '12',
 ('power', 'VARIANT2'): '20',
 ('range', 'VARIANT1'): '200',
 ('range', 'VARIANT2'): '400',
 ('colour', 'VARIANT1'): 'blue',
 ('colour', 'VARIANT2'): 'yellow'}

Or sorted as your example output:

>>> keys_sorted
{('power', 'VARIANT1'): '12',
 ('range', 'VARIANT1'): '200',
 ('colour', 'VARIANT1'): 'blue',
 ('power', 'VARIANT2'): '20',
 ('range', 'VARIANT2'): '400',
 ('colour', 'VARIANT2'): 'yellow'}

Multikey dictionary from 2d array

1 Answers1