遍历列表中的所有连续项对 [英] Iterate over all pairs of consecutive items in a list

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:]):
    ...

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