langchain/docs/examples/data_augmented_generation/question_answering.ipynb

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  {
   "cell_type": "markdown",
   "id": "05859721",
   "metadata": {},
   "source": [
    "# Question Answering\n",
    "\n",
    "This notebook walks through how to use LangChain for question answering over a list of documents. It covers three different types of chaings: `stuff`, `map_reduce`, and `refine`. For a more in depth explanation of what these chain types are, see [here](../../explanation/combine_docs.md)."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "726f4996",
   "metadata": {},
   "source": [
    "### Prepare Data\n",
    "First we prepare the data. For this example we do similarity search over a vector database, but these documents could be fetched in any manner (the point of this notebook to highlight what to do AFTER you fetch the documents)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "17fcbc0f",
   "metadata": {},
   "outputs": [],
   "source": [
    "from langchain.embeddings.openai import OpenAIEmbeddings\n",
    "from langchain.text_splitter import CharacterTextSplitter\n",
    "from langchain.vectorstores.faiss import FAISS\n",
    "from langchain.docstore.document import Document"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "291f0117",
   "metadata": {},
   "outputs": [],
   "source": [
    "with open('../state_of_the_union.txt') as f:\n",
    "    state_of_the_union = f.read()\n",
    "text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)\n",
    "texts = text_splitter.split_text(state_of_the_union)\n",
    "\n",
    "embeddings = OpenAIEmbeddings()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "fd9666a9",
   "metadata": {},
   "outputs": [],
   "source": [
    "docsearch = FAISS.from_texts(texts, embeddings)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "d1eaf6e6",
   "metadata": {},
   "outputs": [],
   "source": [
    "query = \"What did the president say about Justice Breyer\"\n",
    "docs = docsearch.similarity_search(query)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "a16e3453",
   "metadata": {},
   "outputs": [],
   "source": [
    "from langchain.chains.question_answering import load_qa_chain\n",
    "from langchain.llms import OpenAI"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "f78787a0",
   "metadata": {},
   "source": [
    "### The `stuff` Chain\n",
    "\n",
    "This sections shows results of using the `stuff` Chain to do question answering."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "180fd4c1",
   "metadata": {},
   "outputs": [],
   "source": [
    "chain = load_qa_chain(OpenAI(temperature=0), chain_type=\"stuff\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "d145ae31",
   "metadata": {},
   "outputs": [],
   "source": [
    "docs = [Document(page_content=t) for t in texts[:3]]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "77fdf1aa",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'output_text': ' The president did not mention Justice Breyer.'}"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "query = \"What did the president say about Justice Breyer\"\n",
    "chain({\"input_documents\": docs, \"question\": query}, return_only_outputs=True)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "91522e29",
   "metadata": {},
   "source": [
    "### The `map_reduce` Chain\n",
    "\n",
    "This sections shows results of using the `map_reduce` Chain to do question answering."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "b0060f51",
   "metadata": {},
   "outputs": [],
   "source": [
    "chain = load_qa_chain(OpenAI(temperature=0), chain_type=\"map_reduce\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "id": "fbdb9137",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'output_text': ' The president did not mention Justice Breyer.'}"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "query = \"What did the president say about Justice Breyer\"\n",
    "chain({\"input_documents\": docs, \"question\": query}, return_only_outputs=True)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "6ea50ad0",
   "metadata": {},
   "source": [
    "### The `refine` Chain\n",
    "\n",
    "This sections shows results of using the `refine` Chain to do question answering."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "fb167057",
   "metadata": {},
   "outputs": [],
   "source": [
    "chain = load_qa_chain(OpenAI(temperature=0), chain_type=\"refine\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "id": "d8b5286e",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'output_text': \"\\n\\nThe president did not mention Justice Breyer in his speech to the European Parliament about building a coalition of freedom-loving nations to confront Putin, unifying European allies, countering Russia's lies with truth, and enforcing powerful economic sanctions.\"}"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "query = \"What did the president say about Justice Breyer\"\n",
    "chain({\"input_documents\": docs, \"question\": query}, return_only_outputs=True)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "49e9c6d7",
   "metadata": {},
   "outputs": [],
   "source": []
  }
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