fix langchain problem

metagpt/document.py

@@ -11,12 +11,12 @@ from pathlib import Path
 from typing import Optional, Union
 
 import pandas as pd
-from langchain.document_loaders import (
+from langchain.text_splitter import CharacterTextSplitter
+from langchain_community.document_loaders import (
     TextLoader,
     UnstructuredPDFLoader,
     UnstructuredWordDocumentLoader,
 )
-from langchain.text_splitter import CharacterTextSplitter
 from pydantic import BaseModel, ConfigDict, Field
 from tqdm import tqdm
 

requirements.txt

@@ -12,6 +12,7 @@ typer==0.9.0
 # google_api_python_client==2.93.0  # Used by search_engine.py
 lancedb==0.4.0
 langchain==0.1.8
+sqlalchemy==2.0.0  # along with langchain
 loguru==0.6.0
 meilisearch==0.21.0
 numpy>=1.24.3,<1.25.0