how to find the drive in python/cygwin?

[Mayer]

Hello:

I'm running python under cygwin and need to find the drive letter.
Cygwin has a way of calling my drives by a name relative to the Cygwin
directory, so I get things like /home/user rather than
/cygdrive/g/cygwin/home/usr, etc. How can I find the letter of the
drive, or in the above example, the letter 'g'?

My program needs to run on an external media that comes with Cygwin on
it. I have no control over what drive is assigned to that media, but
for some reason, I do need to know the letter.

Please help!

Thanks,

Mayer