交叉列表与固定元素

Question

我知道我可以将两个python列表交错:

[elem for pair in zip(*lists) for elem in pair]

现在我需要将列表与固定元素交错,如:

list = [1, 2, 3, 4]
#  python magic 
output = [1, 0, 2, 0, 3, 0, 4]

Answer 1

一个非常直接的解决方案是:

[elem for x in list for elem in (x, 0)][:-1]

Answer 2

您可以尝试以下itertools魔术:

>>> from itertools import repeat, chain, izip
>>> l = [1, 2, 3, 4]
>>> list(chain.from_iterable(izip(l[:-1], repeat(0)))) + l[-1:]
[1, 0, 2, 0, 3, 0, 4]