hidden file detection

[Lenny G.]

What's the best way to do cross-platform hidden file detection?  I want
to do something like weed-out the files that should be 'hidden' from
os.listdir() (which would be files that start with '.' under Unix,
files that have the hidden attribute set on windows, and whatever it is
that makes Mac files hidden).  Is there a util or lib that does this
for me?

Thanks,
Gary