通过少于生成列表python运行列表

Question

a = [0,1,2,3,4,5,6]
for x in a:
  list(x < 4):

预期输出：[0,1,2,3] 实际输出：[True, True, True, True, False, False, False]

知道如何得到我想要的东西吗？

Answer 1

a = [0,1,2,3,4,5,6]
print ([x for x in a if x<4])

输出;

[0, 1, 2, 3]
>>> 

评论后编辑：它名为list comprehension。

Answer 2

您可以使用filter：

>>> a = [0,1,2,3,4,5,6]
>>> list(filter(lambda x: x < 4, a))
[0, 1, 2, 3]

或itertools.takewhile（如果列表已排序）：

>>> from itertools import takewhile
>>> a = [0,1,2,3,4,5,6]
>>> list(takewhile(lambda x: x < 4, a))
[0, 1, 2, 3]