Traceback during scan

[mdboom]

Traceback (most recent call last):
  File "/usr/lib/python2.7/pdb.py", line 1314, in main
    pdb._runscript(mainpyfile)
  File "/usr/lib/python2.7/pdb.py", line 1233, in _runscript
    self.run(statement)
  File "/usr/lib/python2.7/bdb.py", line 400, in run
    exec cmd in globals, locals
  File "<string>", line 1, in <module>
  File "cli.py", line 3, in <module>
    import sys, cmd, argparse, getpass
  File "/usr/lib/python2.7/cmd.py", line 142, in cmdloop
    stop = self.onecmd(line)
  File "/usr/lib/python2.7/cmd.py", line 221, in onecmd
    return func(arg)
  File "cli.py", line 27, in method
    return func(** { key: vars(args)[key] for key in vars(args) if key != 'action' })
  File "cli.py", line 110, in folder_scan
    FolderManager.scan(folder.id, s)
  File "managers/folder.py", line 94, in scan
    scanner.scan(folder)
  File "scanner.py", line 28, in scan
    self.__scan_file(os.path.join(root, f), folder)
  File "scanner.py", line 77, in __scan_file
    tr.album    = self.__find_album(self.__try_read_tag(tag, 'artist'), self.__try_read_tag(tag, 'album'))
  File "scanner.py", line 83, in __find_album
    ar = self.__find_artist(artist)
  File "scanner.py", line 94, in __find_artist
    ar = filter(lambda a: a.name.lower() == artist.lower(), self.__artists)
  File "scanner.py", line 94, in <lambda>
    ar = filter(lambda a: a.name.lower() == artist.lower(), self.__artists)
AttributeError: 'NoneType' object has no attribute 'lower'

This happens because artist is None in this context, because back in __scan_file, self.__try_read_tag(tag, 'artist') returns None. (I guess I have a broken MP3 file without an artist tag...) Adding a default, i.e. changing to self.__try_read_tag(tag, 'artist', '') seems to help, but I don't know what the right solution is.

BTW: I'm really psyched to have found something I can run on my Sheevaplug that doesn't require something as heavy as Java!