[Python-bugs-list] [ python-Bugs-555042 ] zip() may trigger MemoryError

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Bugs item #555042, was opened at 2002-05-12 02:57
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http://sourceforge.net/tracker/?func=detail&atid=105470&aid=555042&group_id=5470

Category: Python Interpreter Core
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Raymond Hettinger (rhettinger)
>Assigned to: Tim Peters (tim_one)
Summary: zip() may trigger MemoryError

Initial Comment:
The recent optimization of zip() trips a MemoryError 
when the only iterable defining len() is xrange
(sys.maxint).

This error may appear in real code because of reliance 
on zip's ability to truncate to the shortest input 
sequence and because xrange(sys.maxint) was an idiom 
for counting elements with-in a zip.  With the 
introduction of enumerate(), the latter is less likely.

The following code works in Py2.2.1 but fails in 2.3a0
(the tree as of 5/12/2002):

Python 2.3a0 (#29, May 12 2002, 02:30:00) [MSC 32 bit 
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for 
more information.
>>> def g():
...     for i in range(6):
...         yield i
...
>>> zip(g(), xrange(3))
[(0, 0), (1, 1), (2, 2)]
>>> zip(g(), xrange(9))
[(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5)]
>>> import sys
>>> zip(g(), xrange(sys.maxint))
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
MemoryError



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>Comment By: Tim Peters (tim_one)
Date: 2002-05-12 03:03

Message:
Logged In: YES 
user_id=31435

Assigned to me.

----------------------------------------------------------------------

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http://sourceforge.net/tracker/?func=detail&atid=105470&aid=555042&group_id=5470