การจำกัดชุดตัวเลือก

from itertools import product
from math import prod
def variants(groups, limit):
    if type(limit) is not int or limit < 0:
        raise ValueError("limit")
    if not groups: return []
    if any(len(set(g)) != len(g) for g in groups):
        raise ValueError("duplicate option")
    if prod(map(len, groups)) > limit:
        raise ValueError("too many variants")
    return list(product(*groups))