How do I get all the permutations selecting one item from each value list in a dictionary?

Question

Friends, basically, I want to take a dict:

fruit_dict = {'oranges':['big','small'],'apples':['green','yellow','red']}

And get the following list of dictionaries by having all possible permutations between all values of different keys:

output_list = 
[
{'oranges':'big','apples':'green'},
{'oranges':'big','apples':'yellow'},
{'oranges':'big','apples':'red'},
{'oranges':'small','apples':'green'},
{'oranges':'small','apples':'yellow'},
{'oranges':'small','apples':'red'}
]

How to do it? Thanks a million!

Answer 1

What you're looking for isn't the permutations, but the Cartesian product . Think of it like a nested loop.

from itertools import product

fruit_dict = {'oranges':['big','small'],'apples':['green','yellow','red']}    

keys, values = zip(*fruit_dict.items())
print [dict(zip(keys, value_list)) for value_list in product(*values)]

Then you just need to create a new dictionary using your existing keys and each item from the product.

Answer 2

using itertools.product() :

In [94]: dic = {'oranges':['big','small'],'apples':['green','yellow','red']}

In [95]: sort_values=[x[1] for x in sorted(dic.items())]  #sorted values based on keys

In [96]: [dict(zip(sorted(dic.keys()),x)) for x in product(*sort_values)]
Out[96]: 
[{'apples': 'green', 'oranges': 'big'},
 {'apples': 'green', 'oranges': 'small'},
 {'apples': 'yellow', 'oranges': 'big'},
 {'apples': 'yellow', 'oranges': 'small'},
 {'apples': 'red', 'oranges': 'big'},
 {'apples': 'red', 'oranges': 'small'}]