Update app.py

app.py

@@ -1,7 +1,7 @@
 import os
 import gradio as gr
 from langchain.chains import RetrievalQA
-from langchain.vectorstores import Chroma
+from langchain_community.vectorstores import Chroma  # Use langchain_community for vector stores
 from langchain.llms import OpenAI, HuggingFaceHub
 from langchain.embeddings import OpenAIEmbeddings, HuggingFaceEmbeddings
 from langchain.document_loaders import PyPDFLoader