Update retrieval_utils.py

retrieval_utils.py

@@ -16,6 +16,8 @@ from sentence_transformers import SentenceTransformer
 from transformers import DPRQuestionEncoder, DPRQuestionEncoderTokenizer, DPRContextEncoder, DPRContextEncoderTokenizer
 from llm_utils import decoder_for_gpt3
 from utils import entity_cleansing, knowledge_cleansing
+import nltk
+nltk.download('punkt')
 
 wiki_wiki = wikipediaapi.Wikipedia('en')
 nlp = spacy.load("en_core_web_sm")