如何在Python 3中对列表进行分块?
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我发现以下与python2兼容的代码

from itertools import izip_longest
def grouper(n, iterable, padvalue=None):
  "grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
  return izip_longest(*[iter(iterable)]*n, fillvalue=padvalue)

但是,这不适用于Python3。出现以下错误

ImportError: cannot import name izip_longest

有人可以帮忙吗?

I'd like to convert my list of [1,2,3,4,5,6,7,8,9] to [[1,2,3],[4,5,6],[7,8,9]]

编辑

现在与Python3兼容

Code below is adapted from the selected answer. Simply change name from izip_longest to zip_longest.

from itertools import zip_longest
def grouper(n, iterable, padvalue=None):
  "grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
  return zip_longest(*[iter(iterable)]*n, fillvalue=padvalue)

最佳答案

In Python 3's itertools there is a function called zip_longest. It should do the same as izip_longest from Python 2.

Why the change in name? You might also notice that itertools.izip is now gone in Python 3 - that's because in Python 3, the zip built-in function now returns an iterator, whereas in Python 2 it returns a list. Since there's no need for the izip function, it also makes sense to rename the _longest variant for consistency.

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