Use configuration file

negromate/karaoke/commands/karaoke.py

@@ -4,12 +4,14 @@ name = 'karaoke'
 help_text = 'GUI for negromate karaoke'
 
 
-def options(parser):
+def options(parser, config, **kwargs):
     parser.add_argument(
-        'song_folder', type=Path,
-        help="Folder with the song database.")
+        '-s', '--song_folder', type=Path,
+        default=config['global']['song_folder'],
+        help="Folder with the song database, defaults to {}".format(
+            config['global']['song_folder']))
 
 
-def run(args):
+def run(args, **kwargs):
     from ..karaoke import main
-    main(args.song_folder)
+    main(args.song_folder.expanduser())