Update app.py

app.py

@@ -4,6 +4,7 @@ from langchain.text_splitter import RecursiveCharacterTextSplitter
 from sentence_transformers import SentenceTransformer
 from langchain_community.embeddings import HuggingFaceEmbeddings
 #from langchain_community.vectorstores import faiss
+import faiss
 from langchain.prompts import PromptTemplate
 #from langchain.chains import ConversationalRetrievalChain
 #from transformers import pipeline