Update app.py

app.py

@@ -11,7 +11,6 @@ from langchain.indexes import VectorstoreIndexCreator
 from langchain import OpenAI, VectorDBQA
 
 import os
-openai_api_key = os.environ["OPENAI_API_KEY"] 
 
 
 def pdf_to_text(pdf_file, query):
@@ -40,15 +39,13 @@ def pdf_to_text(pdf_file, query):
   llm = HuggingFaceHub(repo_id="google/flan-t5-xl", model_kwargs={"temperature":0, "max_length":512})
   loaders = UnstructuredPDFLoader(pdf_file)
 
-  index = VectorstoreIndexCreator(    
-    embedding=HuggingFaceEmbeddings(),
-    text_splitter= CharacterTextSplitter(chunk_size=1000, chunk_overlap=0).from_loaders(loaders))
+  index = vectorstore.as_retriever()
     #inference
   qa = VectorDBQA.from_chain_type(llm=llm, chain_type="stuff", vectorstore=vectorstore)
   from langchain.chains import RetrievalQA
   chain = RetrievalQA.from_chain_type(llm=llm, 
                                     chain_type="stuff", 
-                                    retriever=index.vectorstore.as_retriever(), 
+                                    retriever=index, 
                                     input_key="question")
   return chain.run(query)