问题描述
给定一个列表
l = [1, 7, 3, 5]
我想遍历所有成对的连续列表项(1,7), (7,3), (3,5),即
I want to iterate over all pairs of consecutive list items (1,7), (7,3), (3,5), i.e.
for i in xrange(len(l) - 1): x = l[i] y = l[i + 1] # do something
我想以更紧凑的方式来做这件事,比如
I would like to do this in a more compact way, like
for x, y in someiterator(l): ...
有没有办法使用内置的 Python 迭代器来做到这一点?我确定 itertools 模块应该有解决方案,但我就是想不通.
Is there a way to do do this using builtin Python iterators? I'm sure the itertools module should have a solution, but I just can't figure it out.
推荐答案
只要使用 拉链
>>> l = [1, 7, 3, 5] >>> for first, second in zip(l, l[1:]): ... print first, second ... 1 7 7 3 3 5
如果您使用 Python 2(不建议),您可能会考虑使用 itertools 中的 izip 函数来处理您不想创建新列表的非常长的列表.
If you use Python 2 (not suggested) you might consider using the izip function in itertools for very long lists where you don't want to create a new list.
import itertools for first, second in itertools.izip(l, l[1:]): ...