calculate playlist duration

- use python's `sum()` method to add durations instead of for loop

server/app/api/album.py

@@ -60,12 +60,16 @@ def get_album():
 
     album.count = len(tracks)
     try:
-        album.duration = albumslib.get_album_duration(tracks)
+        album.duration = sum([t.length for t in tracks])
     except AttributeError:
         album.duration = 0
 
-    if (album.count == 1 and tracks[0].title == album.title
-            and tracks[0].tracknumber == 1 and tracks[0].disknumber == 1):
+    if (
+        album.count == 1
+        and tracks[0].title == album.title
+        and tracks[0].tracknumber == 1
+        and tracks[0].disknumber == 1
+    ):
         album.is_single = True
 
     return {"tracks": tracks, "info": album}

server/app/api/playlist.py

@@ -84,7 +84,12 @@ def get_playlist(playlistid: str):
     playlist = models.Playlist(p)
 
     tracks = playlistlib.create_playlist_tracks(playlist.pretracks)
-    return {"info": serializer.Playlist(playlist), "tracks": tracks}
+
+    duration = sum([t.length for t in tracks])
+    playlist = serializer.Playlist(playlist)
+    playlist.duration = duration
+
+    return {"info": playlist, "tracks": tracks}
 
 
 @playlist_bp.route("/playlist/<playlistid>/update", methods=["PUT"])