to fix the bug when NoneType occur at the end of prompt response

streamlit_app.py

@@ -71,8 +71,9 @@ if st.session_state.messages[-1]["role"] != "assistant":
             placeholder = st.empty()
             full_response = ''
             for chunk in response:
-                full_response += chunk.choices[0].delta.content
-                placeholder.markdown(full_response)
+                if chunk.choices[0].delta.content is not None:
+                    full_response += chunk.choices[0].delta.content
+                    placeholder.markdown(full_response)
             placeholder.markdown(full_response)
     message = {"role": "assistant", "content": full_response}
     st.session_state.messages.append(message)