Update app.py

app.py

@@ -39,8 +39,8 @@ documents= loader.load()
 text_splitter = RecursiveCharacterTextSplitter(chunk_size=1500, chunk_overlap=150)
 texts = text_splitter.split_documents(documents)
 embeddings = OpenAIEmbeddings()
-doc_search = Chroma.from_documents(texts,embeddings)
-chain = VectorDBQA.from_chain_type(llm=OpenAI(temperature=0.0), chain_type="stuff", vectorstore=doc_search)
+vectordb = Chroma.from_documents(texts,embeddings)
+chain = RetrievalQA.from_chain_type(llm=OpenAI(temperature=0.0),chain_type="stuff", retriever=vectordb.as_retriever(),return_source_documents=True)
 
 app = flask.Flask(__name__, template_folder="./")
 # Create a directory in a known location to save files to.