Update app.py

app.py

@@ -53,7 +53,12 @@ def get_conversation_chain(vectorstore):
 
 
 def handle_userinput(user_question):
-    response = st.session_state.conversation({'question': user_question})
+    conversation = st.session_state.conversation
+    if conversation is None:
+        st.error("Conversation not initialized. Please upload PDFs and process them.")
+        return
+
+    response = conversation({'question': user_question})
     st.session_state.chat_history = response['chat_history']
 
     for i, message in enumerate(st.session_state.chat_history):
@@ -65,6 +70,7 @@ def handle_userinput(user_question):
                 "{{MSG}}", message.content), unsafe_allow_html=True)
 
 
+
 def main():
     load_dotenv()
     st.set_page_config(page_title="Chat with multiple PDFs",