NameError：名称“ reduce”未在Python中定义

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问题：NameError：名称“ reduce”未在Python中定义

我正在使用Python 3.2。试过这个：

xor = lambda x,y: (x+y)%2
l = reduce(xor, [1,2,3,4])

并得到以下错误：

l = reduce(xor, [1,2,3,4])
NameError: name 'reduce' is not defined

尝试打印reduce到交互式控制台中-出现此错误：

NameError: name 'reduce' is not defined

是reduce在Python 3.2中真正删除的吗？如果是这样，还有什么选择？

I’m using Python 3.2. Tried this:

xor = lambda x,y: (x+y)%2
l = reduce(xor, [1,2,3,4])

And got the following error:

l = reduce(xor, [1,2,3,4])
NameError: name 'reduce' is not defined

Tried printing reduce into interactive console – got this error:

NameError: name 'reduce' is not defined

Is reduce really removed in Python 3.2? If that’s the case, what’s the alternative?

它已移至functools。

It was moved to functools.

你可以加

from functools import reduce

在使用reduce之前。

You can add

from functools import reduce

before you use the reduce.

或者如果您使用六个库

from six.moves import reduce

Or if you use the six library

from six.moves import reduce

在这种情况下，我认为以下内容是等效的：

l = sum([1,2,3,4]) % 2

唯一的问题是它会产生大量数字，但这也许比重复的模运算更好？

In this case I believe that the following is equivalent:

l = sum([1,2,3,4]) % 2

The only problem with this is that it creates big numbers, but maybe that is better than repeated modulo operations?