Update app.py

app.py

@@ -124,7 +124,7 @@ if __name__ == '__main__':
     if st.button("Reset History"):
         st.session_state['questions'] = []
     
-    if question != "":
+    if question is not None and question != "":
         #q_type = extract_question_type(llm, question)
         with st.chat_message("user"):
             st.markdown(question)