Update app.py

app.py

@@ -2,6 +2,7 @@ import streamlit as st
 #from langchain.chat_models import ChatOpenAI
 from langchain.document_loaders import WebBaseLoader
 from langchain.chains.summarize import load_summarize_chain
+from langchain.text_splitter import RecursiveCharacterTextSplitter
 from bs4 import BeautifulSoup   #WebBaseLoader会需要 用到？
 from langchain import HuggingFaceHub
 import requests