File reading across network (windows)

[Prof. William Battersea]

Hello,

Suppose I have a Vista machine called VISTA and an XP machine called
XP in a workgroup named WORKGROUP. Physically they're connected to a
router and I can see lists of public and shared files on each of them.
How do I address these for IO?

A search suggested that the form open(r"\\server\folder\folder"), but
I tried many combinations guessing what it wants for that path in my
case (r"\\WORKGROUP\VISTA", "\\VISTA\PUBLIC", etc), and none have
worked so far.

Thanks!