Occasional OSError: [Errno 13] Permission denied on Windows

[Alec Wysoker]

Using Python 2.3.5 on Windows XP, I occasionally get OSError: [Errno
13] Permission denied when calling os.remove().  This can occur with a
file that is not used by any other process on the machine, and is
created by the python.exe invocation that is trying to delete it.  It
can happen with various pieces of my system - almost anywhere I try to
delete a file.

I have assumed that the problem is that I was holding on to a handle to
the file that I was trying to remove.  I have scoured my code and close
any handle to the file that I can find.  The intermittent nature of
this problem leads me to believe that I'm not explicitly holding onto a
file object somewhere.

My next theory was that there was some object holding onto a file
handle for which there wasn't an extant reference, but which hadn't
been garbage-collected.  So, I tried removing files like this:

        try:
            os.remove(strPath)
        except OSError:
            # Wild guess that garbage collection might clear errno 13
            gc.collect()
            os.remove(strPath)

This does indeed reduce the frequency of the problem, but it doesn't
make it go away completely.  I really need to fix this problem, because
I'm developing an app that won't survive if it fails to delete its
files.

Thanks,
Alec Wysoker