Chat with your long PDF docs: load_qa_chain, RetrievalQA, VectorstoreIndexCreator, ConversationalRetrievalChain — Are you interested in chatting with your own documents, whether it is a text file, a PDF, or a website? LangChain makes it easy for you to do question answering with your documents. But do you know that there are at least 4 ways to do question answering in…