[ python-Bugs-1603150 ] wave module forgets to close file on exception

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Bugs item #1603150, was opened at 2006-11-26 10:59
Message generated for change (Comment added) made by polivare
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Category: Python Library
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: amerinese (amerinese)
Assigned to: Nobody/Anonymous (nobody)
Summary: wave module forgets to close file on exception

Initial Comment:
I am using python 2.4 on Windows XP SP2

The wave module function:
f = wave.open(file)

In the case that file is a path to the file and the file is not yet opened, wave.open(file) may raise an exception if the file is opened and it does not fulfill the format of a WAV file.  However, it forgets to close the file when the exception is raised keeping other functions from accessing the file (at least until the file is garbage collected).

The regular file opening idiom doesn't work
f = wave.open(file)
try:
   ## do something with the wav file
finally:
   f.close()
Since wave.open(file) raises an exception before return the file name, f can't be closed, but the file is open.

The reason I know this is because I try to delete the file if trying to open it raises an RIFF or not a WAV file exception and it claims the file is locked.

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Comment By: Patricio Olivares (polivare)
Date: 2007-03-14 23:57

Message:
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wave.open expects either a str or a file object. When it gets
a str, it opens the file, works on it, and closes the file. All of
this in the inner scope of the wave.open function.

But if the file pointed by the str is not a correct wav format,
then wave.open throws wave.Error but *doesn't close the file*. It
assumes that the file will be garbage collected and then closed but
that does not happen. I believe that it has to do with the "Note"
at <http://docs.python.org/ref/customization.html#l2h-177>

The problem is noted mostly on the interactive interpreter on
windows  because on windows you can't delete/move a file if it's being
used
by another process so you need to close the interpreter to release
the file.


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Comment By: A.M. Kuchling (akuchling)
Date: 2006-12-19 16:59

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Try putting the Wave.open() inside the try...finally.



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