प्रोग्राम की सुविधाएँ · सामान्य नियमों में निम की चालें

def nim_move(piles):
    if type(piles) not in (list, tuple) or len(piles) > 128 or any(type(v) is not int or not 0 <= v <= 10**9 for v in piles):
        raise ValueError("nim.piles")
    balance = 0
    for pile in piles:
        balance ^= pile
    if balance == 0:
        return None
    for index, pile in enumerate(piles):
        reduced = pile ^ balance
        if reduced < pile:
            return index, reduced