Update app.py

app.py

@@ -97,6 +97,8 @@ def main():
     st.title("Menu:")
     pdf_docs = st.file_uploader("Upload your PDF File and Click on the Submit & Process Button", accept_multiple_files=False, key="pdf_uploader")
     query = st.text_input("Ask a Question from the PDF File", key="query")
+    if 'messages' not in st.session_state:
+        st.session_state.messages = [{'role': 'assistant', "content": 'Hello! Upload a PDF and ask me anything about its content.'}]
     if st.button("Submit & Process", key="process_button"):
         with st.spinner("Processing..."):
             raw_text = get_pdf(pdf_docs)