To apply the logic of “not any” you would want to check if it is any of the valid results then invert. (NOR)
if not (diff == "1" or diff == "2" or diff == "3"):
Or applying DeMorgan’s theorem this would be equivelent to “not equal to 1 AND not equal to 2 AND not equal to 3”
if diff != "1" and diff != "2" and diff != "3":
of course python also has the in
and not in
operator which makes this much cleaner:
if diff not in ("1", "2", "3"):
solved Why doesn’t this “is not” if statement work?