- present_track_ids = set([compat_str(track['id']) for track in tracks if track.get('id')])
- missing_track_ids = set(map(compat_str, track_ids)) - set(present_track_ids)
+ present_track_ids = set([
+ compat_str(track['id'])
+ for track in tracks if track.get('id')])
+ missing_track_ids = [
+ track_id for track_id in track_ids
+ if track_id not in present_track_ids]