Update app.py

app.py

@@ -8,6 +8,9 @@ from io import StringIO
 import time
 
 def print_time(start, end):
+    # Initialize chat history
+    if "messages" not in st.session_state:
+        st.session_state.messages = []
     st.session_state.messages.append({"role": "assistant", "content": f"Execution time: {end - start} seconds"})
 
 # Streamlit app