Update app.py

app.py

@@ -418,6 +418,7 @@ def main():
                         chat_engine_bandi.reset()                
                     print(chat_engine_bandi.chat_history)
                     print(memory_bandi)
+                    stream_response = None
                     stream_response = chat_engine_bandi.stream_chat(user_message)
                     print("risposta con chat engine")
                     responseHTML = ""
@@ -442,6 +443,7 @@ def main():
                         chat_engine_bandi_sistema_puglia.reset()                
                     print(chat_engine_bandi_sistema_puglia.chat_history)
                     print(memory_bandi_sistema_puglia)
+                    stream_response = None
                     stream_response = chat_engine_bandi_sistema_puglia.stream_chat(user_message)
                     print("risposta con chat engine")
                     responseHTML = "" 
@@ -466,6 +468,7 @@ def main():
                     response_synthesizer = get_response_synthesizer(streaming=True,response_mode="tree_summarize",text_qa_template=text_qa_template)
                     query_engine = None
                     query_engine = RetrieverQueryEngine(retriever=retriever, response_synthesizer=response_synthesizer)
+                    stream_response = None
                     stream_response = query_engine.query(user_message)
                     print("risposta con query engine")
                     responseHTML = ""
@@ -482,6 +485,7 @@ def main():
                     response_synthesizer = get_response_synthesizer(streaming=True,response_mode="compact",text_qa_template=text_qa_template, refine_template=refine_template)
                     query_engine = None
                     query_engine = RetrieverQueryEngine(retriever=retriever, response_synthesizer=response_synthesizer)
+                    stream_response = None
                     stream_response = query_engine.query(user_message)
                     print("risposta con query engine")
                     responseHTML = ""