Update app.py

app.py

@@ -104,6 +104,8 @@ def conversational_chat(query):
     result = chain({"question": query, "chat_history": st.session_state['history']})
     st.session_state['history'].append((query, result["answer"]))   
     return result["answer"]
+if 'history' not in st.session_state:
+    st.session_state['history'] = []
 # Initialize session state if not already done
 if 'past' not in st.session_state:
     st.session_state['past'] = ["チャットはここから"]