[Python-bugs-list] [ python-Bugs-476138 ] tempfile behavior across platforms

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Bugs item #476138, was opened at 2001-10-29 13:14
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Category: Python Library
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Submitted By: Jeremy Hylton (jhylton)
Assigned to: Tim Peters (tim_one)
Summary: tempfile behavior across platforms

Initial Comment:
The object returned by TemporaryFile.tempfile() has a 
close() method.  On Unix, this is a builtin file 
object's close method.  On Windows, it is a 
TemporaryFileWrapper object's close method.

The two have different semantics, which limits the 
utility of the module in code that should run on both 
platforms.  There are two differences:

   - The close() method on Windows unlinks the 
     file after closing it.  The close() method
     on Unix does not.

   - Calling close() on a closed tempfile raises
     an exception on Windows, but has no effect
     on Unix.  (This is a consequence of the
     previous difference.  The second attempt to
     unlink the file fails.)

I think the sensible fix is to catch and ignore failed 
unlink calls on Windows.


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>Comment By: Tim Peters (tim_one)
Date: 2001-10-29 13:48

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tempfiles can now be closed any number of times on Windows, 
although if the unlink fails on Windows something is wrong, 
so I don't suppress that:

Lib/tempfile.py; new revision: 1.32
Lib/test/test_tempfile.py; initial revision: 1.1

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Comment By: Tim Peters (tim_one)
Date: 2001-10-29 13:31

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Well, on Unix the file is unlinked before the tempfile 
*create* returns.  That isn't possible on Windows.

I agree a tempfile should-- like a Python file object --be 
closeable any number of times, although it should raise an 
exception if the *first* attempt to unlink it fails.

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Comment By: Guido van Rossum (gvanrossum)
Date: 2001-10-29 13:21

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The first difference doesn't really bother you, does it? On
Unix, the file has already been unlinked when it was first
created.

It sounds like the real difference you're after is that the
Unix version allows calling close() more than once, because
open files can be closed more than once.

I think this is a useful semantic to retain, and propose to
fix it as you suggest.

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