Update app.py

app.py

@@ -155,17 +155,16 @@ fall_back_prompt = ChatPromptTemplate.from_template(fall_back_template)
 
 
 chat_history = lambda x: "\n".join(
-            [
-                (
-                    f"human: {msg.content}"
-                    if isinstance(msg, HumanMessage)
-                    else f"AI: {msg.content}"
-                )
-                for msg in x["chat_history"]
-            ]
+    [
+        (
+            f"human: {msg.content}" if isinstance(msg, HumanMessage) else f"AI: {msg.content}"
+        )
+        for msg in x["chat_history"] if hasattr(msg, "content")
+    ]
 )
 
 
+
 fallback_chain  = (
     {"chat_history":chat_history , "query":itemgetter("query")}
     | fall_back_prompt