Update app.py

app.py

@@ -1,4 +1,16 @@
 import streamlit as st
+
 uploaded_file = st.sidebar.file_uploader("上传文件")
 if uploaded_file is not None:
-    st.session_state.uploaded_file = uploaded_file
+    st.session_state.previous_file = uploaded_file
+else:
+    st.warning("请上传文档文件")
+    st.stop()    
+    
+if "uploaded_file" in st.session_state:
+    if st.session_state.uploaded_file is not None:
+        if st.session_state.uploaded_file != st.session_state.previous_file:
+            # 重新生成向量并保存
+            documents = process_file(st.session_state.uploaded_file)
+            st.session_state.new_index = VectorStoreIndex.from_documents(documents)
+            st.session_state.previous_file = st.session_state.uploaded_file