Update app.py

app.py

@@ -20,7 +20,10 @@ if st.button("Submit", type="primary"):
         stream=True,
     ):
         content.append(chunk["choices"][0].get("delta", {}).get("content"))
-        result = "".join(content).strip()
+        if content is not None:
+          result = "".join(content).strip()
+        else:
+          result = ""
         result = result.replace("\n", "")
         res_box.markdown(result)
 st.markdown("----")