don't reuse playlists

recommendation_engine.py

@@ -96,13 +96,13 @@ class Engine:
         playlists = playlists[channels['userKeywords']:]
         # For each playlist, compute global keyword score
         score = {}
-        for playlist in self.playlists:
+        for playlist in playlists:
             score[playlist['name']] = random.random()
             for tag in [tag for tag in playlist['tags'] if tag in sliders]:
                 score[playlist['name']] += sliders[tag]
         # Select highest scoring playlists
         playlists = sorted(
-            self.playlists,
+            playlists,
             key=lambda playlist: -score[playlist['name']]
         )
         videos += playlists[:channels['globalKeywords']]