Update app.py

app.py

@@ -309,9 +309,12 @@ def ask_questions_abt_dataframes(file,file_ext):
 
 
 def upload_file(chatbot_history,file_uploaded):
+  file_ext = os.path.splitext(file_uploaded.name)[-1]
+  if file_ext not in ['.csv','.docx','.xlsx','.pdf','.txt']:
+    return  chatbot_history + [(None, 'Invalid file format. We currently only csv, docx, pdf, txt, xlsx file extensions.')]  
 
   print(file_uploaded.__class__)
-  file_ext = os.path.splitext(file_uploaded.name)[-1]
+  
   if file_ext not in ['.csv','.xlsx']:
     build_embeddings(file_uploaded.name,file_ext)
   else: