langchain python-dotenv ipykernel langchain_community pypdf bs4 arxiv pymupdf fitz wikipedia langchain-text-splitters streamlit python-docx pdfplumber docx2txt openai langchain python-dotenv xlsxwriter python-docx lxml==5.2.1 docx langchain_core langchain_groq langchain_openai fastapi langserve sse_starlette uvicorn