列表合并保留最大长度

import itertools

w, x, y, z = [], [1], [2, 3], [4, 5, 6]

longest_wxyz = itertools.zip_longest(w, x, y, z)

print(list(longest_wxyz))

结果:
[(None, 1, 2, 4), (None, None, 3, 5), (None, None, None, 6)]

来源：https://www.cnblogs.com/hankleo/p/11647277.html