Update backend/rag/knowledge_base.py

backend/rag/knowledge_base.py

@@ -23,7 +23,7 @@ import fitz  # PyMuPDF
 from PIL import Image
 from langchain_core.documents import Document as LangchainDocument
 from langchain_classic.retrievers import BM25Retriever, EnsembleRetriever
-from langchain.text_splitter import NLTKTextSplitter
+from langchain_text_splitters import NLTKTextSplitter
 from langchain_community.vectorstores import Chroma
 from tqdm import tqdm