Update app.py

app.py

@@ -98,6 +98,10 @@ def prepare_conversation(vectorstore):
 
 def process_user_question(user_question):
 
+    if ! user_question :
+        print('question is null')
+        return
+
     response = st.session_state.conversation({'question': user_question})
     # response = st.session_state.conversation({'summarization': user_question})
     st.session_state.chat_history = response['chat_history']