Update app.py

app.py

@@ -2,7 +2,7 @@ import os
 from langchain.document_loaders import PyPDFLoader
 from langchain.text_splitter import RecursiveCharacterTextSplitter
 from langchain.chat_models import ChatOpenAI
-from langchain import OpenAI
+from langchain.llms import OpenAI
 from langchain import PromptTemplate
 from langchain.chains.summarize import load_summarize_chain
 import gradio as gr