Is it possible to get the full path of the file on the user's computer being uploaded to my site?
Using os.path.abspath(fileitem.filename) simply gets me the address of where my script is executing from on my shared hosting server.
FYI: fileitem = form['file']  and form = cgi.FieldStorage()
No, that information isn't sent by the user, so it's not available on your end
Get Path of Uploaded File using Python