spisok = [2, 4, 13, 3, 10, 5, 6, 8, 12, 1, 7, 11, 9]
n = 3
for i in range(0, len(spisok), n):
rrr = spisok[i:i + n]
print(rrr)
>>> [2, 4, 13]
[3, 10, 5]
[6, 8, 12]
[1, 7, 11]
[9]
Как получить в переменные списки[2, 4, 13], [3, 10, 5] и тд