import streamlit as st

uploaded_file = st.sidebar.file_uploader("上传文件")

if uploaded_file is not None:
    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