Execute function on all possible combinations of parameters

Question

I have sets of values that I want to apply as parameters to a function:

params = {
    'a': [1, 2, 3],
    'b': [5, 6, 7],
    'x': [None, 'eleven', 'f'],
    # et cetera
}

I want to run myfunc() with all possible combinations, so myfunc(a=1, b=5, x=None ...), myfunc(a=2, b=5, x=None ...) ... myfunc(a=3, b=7, x='f' ...). Is there something (for example in itertools) that can help? I thought about using itertools.product() but that doesn't keep the names of the parameters and just gives me tuples of the combinations.

Answer 1

You can use itertools.product to get all combinations of arguments:

>>> import itertools
>>> for xs in itertools.product([1,2], [5,6], ['eleven', 'f']):
...     print(xs)
... 
(1, 5, 'eleven')
(1, 5, 'f')
(1, 6, 'eleven')
(1, 6, 'f')
(2, 5, 'eleven')
(2, 5, 'f')
(2, 6, 'eleven')
(2, 6, 'f')

With Argument list unpacking, you can call myfunc with all combinations of keyword arguments:

params = {
    'a': [1, 2, 3],
    'b': [5, 6, 7],
    'x': [None, 'eleven', 'f'],
}

def myfunc(**args):
    print(args)

import itertools
keys = list(params)
for values in itertools.product(*map(params.get, keys)):
    myfunc(**dict(zip(keys, values)))

output:

{'a': 1, 'x': None, 'b': 5}
{'a': 1, 'x': None, 'b': 6}
{'a': 1, 'x': None, 'b': 7}
{'a': 1, 'x': 'eleven', 'b': 5}
{'a': 1, 'x': 'eleven', 'b': 6}
{'a': 1, 'x': 'eleven', 'b': 7}
{'a': 1, 'x': 'f', 'b': 5}
...

Answer 2

I developed combu which is that solution.

1. Install combu

pip install combu

2. Use combu

# Case 1: Directly call
import combu

for res, param in combu.execute(myfunc, params):
    print(res, params)

# Case 2: Use class
from combu import Combu

comb = Combu(myfunc)

for res, param in comb.execute(params):
    print(res, params)