Update app.py

app.py

@@ -8,6 +8,10 @@ def update_scores(winner, loser, k_factor=100):
   return winner, loser
 
 def vote_startup(songs_df):
+    try:
+        songs_df = songs_df[["elo_score",	"artist",	"song_title"]]
+    except:
+        songs_df = pd.DataFrame(columns=['elo_score', 'artist', 'song_title'])
   if len(songs_df)>0:
       sample = songs_df.sample(frac=1).iloc[0]
       song_title, artist = sample["song_title"], sample["artist"]