Python 怎么筛选list中特定位置的数据

[XSEL]

a = [0,1,2,3,4,5,6,7,8,9]
比如这个列表中我想只留下[0,4,8]
每隔四个，有什么办法

[混沌鳄鱼]

方法挺多的，我随便写两个

>>> a = [0,1,2,3,4,5,6,7,8,9]
>>> from functools import reduce
>>> reduce(lambda x,y: x + a[y:y+2], range(0,len(a), 4),[])
[0, 1, 4, 5, 8, 9]
>>> from itertools import chain
>>> list(chain(*zip(a[::4],a[1::4])))
[0, 1, 4, 5, 8, 9]

当然了，要写的hacker一些可以这样

>>> sum([a[i:i+2] for i in range(0,len(a), 4)],[])
[0, 1, 4, 5, 8, 9]
>>> 

[陈年椰子]

a = [0,1,2,3,4,5,6,7,8,9]
b = filter(lambda x:x%4==0,a  )

这种效果？

[混沌鳄鱼]

引用 1 楼 seakingx 的回复:

a = [0,1,2,3,4,5,6,7,8,9]
b = filter(lambda x:x%4==0,a  )

这种效果？

参考一下

>>> a = [0,1,2,3,4,5,6,7,8,9]
>>> a[::4]
[0, 4, 8]

[陈年椰子]

鳄鱼大神的方法好！

[XSEL]

引用 2 楼 xpresslink 的回复:

[quote=引用 1 楼 seakingx 的回复:]

a = [0,1,2,3,4,5,6,7,8,9]
b = filter(lambda x:x%4==0,a  )

这种效果？

参考一下

>>> a = [0,1,2,3,4,5,6,7,8,9]
>>> a[::4]
[0, 4, 8]

[/quote] 感谢！那有没有办法显示[0,1,4,5,8,9]??