[docs] Fwd: There is bug about the built-in function reduce in the document

Tue Sep 11 04:42:31 CEST 2012

---------- Forwarded message ----------
From: Shafreeck Sea <renenglish at gmail.com>
Date: 2012年9月6日
Subject: There is bug about the built-in function reduce in the document
To: docs at python.org
Hi all:
I found a bug in the document about reduce :
http://docs.python.org/library/functions.html#reduce
Here is the patch:
def reduce(function, iterable, initializer=None):
 it = iter(iterable)
 if initializer is None:
 try:
 initializer = next(it)
 except StopIteration:
 raise TypeError('reduce() of empty sequence with no initial
value')
 accum_value = initializer
- for x in iterable:
+ for x in it:
 accum_value = function(accum_value, x)
 return accum_value
It duplicated the first element of iterable
For example:
In [4]: reduce(lambda x,y:x+y, [1,2,3,4])
Out[4]: 10
In [5]: docreduce.reduce(lambda x,y:x+y ,[1,2,3,4])
Out[5]: 11
Sorry for my poor english !
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