def candidatekeys(data: Table, maxcols: int = 1) -> Iterable[Tuple[int, ...]]:
cols = list(transpose(data))
return map(
tuple,
dropsupersets(
map(set,
(localcolids for i in range(1, maxcols + 1)
for localcolids in combinations(range(len(cols)), i)
if isdistinct(transpose(cols[j] for j in localcolids))))))
def test_isdistinct():
assert isdistinct([1, 2, 3]) is True
assert isdistinct([1, 2, 1]) is False
assert isdistinct("Hello") is False
assert isdistinct("World") is True
assert isdistinct(iter([1, 2, 3])) is True
assert isdistinct(iter([1, 2, 1])) is False
