import streamlit as st
import os
from langchain.chains import RetrievalQA, ConversationalRetrievalChain
from langchain.chat_models import ChatOpenAI
from langchain.document_loaders import TextLoader
from langchain.text_splitter import CharacterTextSplitter
from langchain.embeddings import OpenAIEmbeddings
from langchain.vectorstores import FAISS
from langchain.memory import ConversationBufferMemory
import re

# Initialize the Streamlit app
st.title('Document-Based Q&A System')