Update app.py

app.py

@@ -29,7 +29,8 @@ from langchain_community.embeddings import HuggingFaceEmbeddings
 from sentence_transformers import SentenceTransformer
 # from langchain.retrievers import BM25Retriever
 from langchain_community.retrievers import BM25Retriever
-from langchain.schema import Document
+# from langchain.schema import Document
+from langchain_core.schema import Document
 from langchain_core.tools import tool
 
 # =======================================================================