Problem with os.listdir and delay with unreachable network drives onWindows

[Read Roberts]

I wrote my own directory browser in order to get around a bug where
tkFileDialog.askdirectory() can't handle non-ascii paths. However, I
have a problem where I call os.listdir() on a mapped network drive,
e.g. os.listdir("Z:\\"), and if the network drive is unavailable, the
UI hangs until the OS returns with an exception because the network
shared drive is unavailable.

I would like to work around this by simply not looking into mapped
drives that are not currently mounted. Is there some way to check
the status of mapped drive to see if it is currently mounted, or a
better solution? ( I use the call win32api.GetLogicalDriveStrings()
to get the list of available drives).

Also, is there any way to enumerate remote volumes that are mounted
by not mapped? I can't easily find this in the win32 stuff or via
googling. The win32net calls to enumerate servers and shares sound
likely, but don't show such volumes on my system, although I may not
be using the right arguments.

I have the current Windows binary install of Python 2.3.4 on my
Windows XP system.