Update app.py

app.py

@@ -231,9 +231,10 @@ def keyphrase_generator(article_link, model_1, model_2, max_num_keywords):
     
 
   df_new = pd.DataFrame(dict([ (k,pd.Series(v)) for k,v in mydict.items() ]))
+  df_final = df_new.fillna(' ')
 
   
-  return df_new
+  return df_final
   
 
 igen_pubmed = gr.Interface(keyphrase_generator,