Update app.py

app.py

@@ -5,11 +5,10 @@ from langchain.document_loaders import OnlinePDFLoader
 from langchain.text_splitter import CharacterTextSplitter
 text_splitter = CharacterTextSplitter(chunk_size=350, chunk_overlap=0)
 
-from langchain.llms import HuggingFaceHub
-flan_ul2 = HuggingFaceHub(repo_id="google/flan-ul2", model_kwargs={"temperature":0.1, "max_new_tokens":300})
+from langchain.llms import OpenAI
 
-from langchain.embeddings import HuggingFaceHubEmbeddings
-embeddings = HuggingFaceHubEmbeddings()
+from langchain.embeddings import OpenAIEmbeddings
+embeddings = OpenAIEmbeddings()
 
 from langchain.vectorstores import Chroma
 
@@ -23,7 +22,7 @@ def pdf_changes(pdf_doc):
     db = Chroma.from_documents(texts, embeddings)
     retriever = db.as_retriever()
     global qa 
-    qa = RetrievalQA.from_chain_type(llm=flan_ul2, chain_type="stuff", retriever=retriever, return_source_documents=True)
+    qa = RetrievalQA.from_chain_type(llm=OpenAI(), chain_type="stuff", retriever=retriever, return_source_documents=True)
     return "Ready"
 
 def add_text(history, text):