Sochitanie

def next_choose(c, N, k):
    if len(c) < k:
        c.clear()
        c.extend(range(k))
        return tuple(range(k))
    else:
        l = list(c)
        l.extend([N, 0])
    j = 0
    while l[j] + 1 == l[j + 1]:
        c[j] = j
        j += 1
    if j == k:
        return None
    c[j] += 1
    return tuple(c)