Update app.py

app.py

@@ -13,6 +13,7 @@ Biden=B.read()
 text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
 texts = text_splitter.split_text(Biden)
 db = Chroma.from_documents(texts, embeddings)
+retriever = db.as_retriever()
 qa = RetrievalQA.from_chain_type(llm=llm, chain_type="stuff", retriever=retriever)
 def answer(query):
   out=qa.run(query)