Update app.py

app.py

@@ -71,16 +71,11 @@ def initialize(arxivcode):
 
     return RAG(llm, docs, embeddings)
 
-rag_chain = None 
-
 def handle_prompt(message, history, arxivcode): 
-    try:
-        rag_chain
-    except UnboundLocalError:
+    if rag_chain is None:
         # initialize RAG chain 
-        # RAG chain
         rag_chain = initialize(arxivcode)
-        global rag_chain
+
         
     try:
         # Stream output
@@ -103,5 +98,7 @@ with gr.Blocks() as demo:
                    additional_inputs=[arxiv_code]
                   )
                           
+if __name__=='__main__': 
+    rag_chain = None 
 
-demo.launch()
+    demo.launch()