Basically what I am looking for is the equivalent of itertools.product but for dicts.

For example, say I want to test a function for all combinations of its keyword arguments, I would like to pass lists of permissible values for each keyword argument and then get back a list of dicts.

kwargs_options = {"debug": ["on", "off"], "locale":["de_DE", "en_US", "fr_FR"]

expected ouput:

[{'debug': 'on', 'locale': 'de_DE'},{'debug': 'on', 'locale': 'en_US'},{'debug': 'on', 'locale': 'fr_FR'},{'debug': 'off', 'locale': 'de_DE'},{'debug': 'off', 'locale': 'en_US'},{'debug': 'off', 'locale': 'fr_FR'}]

In order to have a similar API to itertools.product this should return an iterator, which can then be wrapped with a call to list(...) if desired.

Example call:

list(dictproduct(kwargs_options}))

This is similar to Combinations from dictionary with list values using Python but returns a list of two-element dicts rather than two single-element dicts.

This is what I have come up with:

from itertools import productdef dictproduct(dct):for t in product(*dct.itervalues()):yield dict(zip(dct.iterkeys(), t))

which gives us

>>> list(dictproduct({"debug":["on", "off"], "locale":["de_DE", "en_US", "fr_FR"]}))
[{'debug': 'on', 'locale': 'de_DE'},{'debug': 'on', 'locale': 'en_US'},{'debug': 'on', 'locale': 'fr_FR'},{'debug': 'off', 'locale': 'de_DE'},{'debug': 'off', 'locale': 'en_US'},{'debug': 'off', 'locale': 'fr_FR'}]

This can also be used to efficiently call a function with all combinations of keyword arguments:

def kwproduct(**kwargs):return dictproduct(kwargs)def f(x, y):return 10*x + yfor kwargs in kwproduct(x=[1,2], y=[3,4,5]):print "f({x},{y})={z}".format(z=f(**kwargs), **kwargs)

output:

f(1,3)=13
f(2,3)=23
f(1,4)=14
f(2,4)=24
f(1,5)=15
f(2,5)=25

The benefit of kwproduct over dictproduct is that you don't need to create a dict but it obviously limits you to use valid argument names as keys.