fix tag function logging; don't try to tag with None

delojza.py

@@ -134,8 +134,12 @@ class DelojzaBot:
         artist = artist.strip() if artist else None
         title = title.strip() if title else None
 
+        if title is None and artist is None:
+            message.reply_text("Tried tagging, found nothing :(")
+            return
+
         message.reply_text("Tagging as \"{}\" by \"{}\"\nvia {}".format(title, artist, source))
-        self.logger.info("Tagging %s w/ $s - $s [%s]...".format(filepath, title, artist, source))
+        self.logger.info("Tagging {} w/ {} - {} [{}]...".format(filepath, title, artist, source))
         try:
             id3 = mutagen.id3.ID3(filepath)
         except mutagen.id3.ID3NoHeaderError: