Agnostic fetching

[jorpheus]

OK, that sounds stupid. Anyway, I've been learning Python for some
time now, and am currently having fun with the urllib and urllib2
modules, but have run into a problem(?) - is there any way to fetch
(urllib.retrieve) files from a server without knowing the filenames?
For instance, there is smth like folder/spam.egg, folder/
unpredictable.egg and so on. If not, perhaps some kind of glob to
create a list of existing files? I'd really appreciate some help,
since I'm really out of my (newb) depth here.