Update app.py

app.py

@@ -33,6 +33,7 @@ from functools import lru_cache
 from langchain.retrievers import MultiQueryRetriever
 from langchain_huggingface.llms import HuggingFacePipeline
 from transformers import pipeline
+from sentence_transformers import SentenceTransformer, util
 from sklearn.model_selection import ParameterGrid
 from tqdm import tqdm
 import random