return qa_chain

app.py

@@ -5,7 +5,6 @@ import streamlit as st
 from PyPDF2 import PdfReader
 from langchain.text_splitter import CharacterTextSplitter
 from langchain.chains.question_answering import load_qa_chain
-from langchain.chains import load_qa_with_sources_chain
 from langchain_huggingface import HuggingFaceEmbeddings
 from langchain_community.vectorstores import FAISS
 from langchain_community.llms import HuggingFacePipeline