[ python-Bugs-1615275 ] tempile.TemporaryFile differences between linux and windows

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Bugs item #1615275, was opened at 2006-12-13 16:20
Message generated for change (Comment added) made by draghuram
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Category: Extension Modules
Group: Platform-specific
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: hirzel (hirzel)
Assigned to: Nobody/Anonymous (nobody)
Summary: tempile.TemporaryFile differences between linux and windows

Initial Comment:
This bug came up when trying to write a numpy array to a tempfile.TemporaryFile() using the numpy 'tofile' method on windows using python 2.4.  

with a numpy array 'a', and a TemporaryFile 'f', 
on windows:
>>> a.tofile(f)

throws an IOError, where on Linux it does not.
On windows, you must use a.tofile(f.file)

The cause of this difference is that in windows, tempfile.TemporaryFile() returns <type 'instance'> that has a 'file'  attribute of <type 'file'>, whereas in linux tempfile.TemporaryFile() returns <type 'file'> and there is no 'file' attribute.  

Ideally, the windows version would align with linux, and the module documentation and TemporaryFile() would return a <type 'file'>.  If this is not possible, it seems like the linux version and docs should be changed to match the windows version to align cross-platform behavior.  At least, that seems to be the shared opinion of this thread from the mailing list: numpy-discussion.  http://www.mail-archive.com/numpy-discussion@scipy.org/msg00271.html

To my knowledge, while platform differences in tempfile have been reported in the past, this one has not.



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Comment By: Raghuram Devarakonda (draghuram)
Date: 2007-03-28 10:43

Message:
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I used the following code to reproduce the problem on windows XP.

----------
import array
import tempfile

testarray = array.array('B')
testarray.fromstring("\x00\x00\x00")
f = tempfile.TemporaryFile()
testarray.tofile(f)
-----------

This works fine on linux but on windows, it gives the following error:

-------------
Traceback (most recent call last):
  File "c:\rags\tofile.py", line 7, in <module>
    testarray.tofile(f)
TypeError: arg must be open file
-------------

Changing "f" to "f.file" seems to work, though, as explained in the
initial post. So this may be the same problem as OP reported even though I
am getting TypeError and he mentioned IOError. 

I tested with 2.4 and 2.5 as I don't know how to set up python development
environment on windows (yet). I will see if I can set that up first before
working on the "fix". 

Raghu.





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