如何从python中提取数字列表中的非空元素

Question

我目前有一个清单如下：

[
    [0], [2], [4], [6], [7], [9], [20], [24],
    [], [26], [], [27], [], [], [], [],
    [], [], [], [], [], [], [], [],
    [], []
] 

我怎样才能把它转换成[0, 2, 4, 6, 7, 9, 20, 24, 26, 27]

Answer 1

只需使用列表理解：

out = [l[0] for l in list1 if len(l) > 0]

Answer 2

假设输入列表为list1，则使用itertools.chain

from itertools import chain

out = list(chain.from_iterable(list1))

输出：[0, 2, 4, 6, 7, 9, 20, 24, 26, 27]