Update app.py

app.py

@@ -13,7 +13,6 @@ from langchain_community.chat_message_histories.streamlit import StreamlitChatMe
 from langchain.prompts import PromptTemplate
 from langchain.chains.question_answering import load_qa_chain
 from langchain.vectorstores import Chroma
-from langchain.retrievers import mmr_retriever
 from utills import load_txt_documents , split_docs, chroma_db, load_uploaded_documents
 
 # Initialize variables and paths