How to generate all combination from values in dict of lists in Python

Question

I would like to generate all combinations of values which are in lists indexed in a dict:

{'A':['D','E'],'B':['F','G','H'],'C':['I','J']} 

Each time, one item of each dict entry would be picked and combined to items from other keys, so I have:

['D','F','I'] ['D','F','J'] ['D','G','I'] ['D','G','J'] ['D','H','I'] ... ['E','H','J'] 

I know there is a something to generate combinations of items in list in itertools but I don't think I can use it here since I have different "pools" of values.

Is there any existing solution to do this, or how should I proceed to do it myself, I am quite stuck with this nested structure.

Answer 1

import itertools as it  my_dict={'A':['D','E'],'B':['F','G','H'],'C':['I','J']} allNames = sorted(my_dict) combinations = it.product(*(my_dict[Name] for Name in allNames)) print(list(combinations)) 

Which prints:

[('D', 'F', 'I'), ('D', 'F', 'J'), ('D', 'G', 'I'), ('D', 'G', 'J'), ('D', 'H', 'I'), ('D', 'H', 'J'), ('E', 'F', 'I'), ('E', 'F', 'J'), ('E', 'G', 'I'), ('E', 'G', 'J'), ('E', 'H', 'I'), ('E', 'H', 'J')] 

Answer 2

If you want to keep the key:value in the permutations you can use:

import itertools keys, values = zip(*my_dict.items()) permutations_dicts = [dict(zip(keys, v)) for v in itertools.product(*values)] 

this will provide you a list of dicts with the permutations:

print(permutations_dicts) [{'A':'D', 'B':'F', 'C':'I'},   {'A':'D', 'B':'F', 'C':'J'},  ...  ] 

disclaimer not exactly what the OP was asking, but google send me here looking for that.