langchain/docs/integrations/vectara/vectara_text_generation.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Vectara Text Generation\n",
    "\n",
    "This notebook is based on [text generation](https://github.com/hwchase17/langchain/blob/master/docs/modules/chains/index_examples/vector_db_text_generation.ipynb) notebook and adapted to Vectara."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Prepare Data\n",
    "\n",
    "First, we prepare the data. For this example, we fetch a documentation site that consists of markdown files hosted on Github and split them into small enough Documents."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import os\n",
    "from langchain.llms import OpenAI\n",
    "from langchain.docstore.document import Document\n",
    "import requests\n",
    "from langchain.vectorstores import Vectara\n",
    "from langchain.text_splitter import CharacterTextSplitter\n",
    "from langchain.prompts import PromptTemplate\n",
    "import pathlib\n",
    "import subprocess\n",
    "import tempfile"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "Cloning into '.'...\n"
     ]
    }
   ],
   "source": [
    "def get_github_docs(repo_owner, repo_name):\n",
    "    with tempfile.TemporaryDirectory() as d:\n",
    "        subprocess.check_call(\n",
    "            f\"git clone --depth 1 https://github.com/{repo_owner}/{repo_name}.git .\",\n",
    "            cwd=d,\n",
    "            shell=True,\n",
    "        )\n",
    "        git_sha = (\n",
    "            subprocess.check_output(\"git rev-parse HEAD\", shell=True, cwd=d)\n",
    "            .decode(\"utf-8\")\n",
    "            .strip()\n",
    "        )\n",
    "        repo_path = pathlib.Path(d)\n",
    "        markdown_files = list(repo_path.glob(\"*/*.md\")) + list(\n",
    "            repo_path.glob(\"*/*.mdx\")\n",
    "        )\n",
    "        for markdown_file in markdown_files:\n",
    "            with open(markdown_file, \"r\") as f:\n",
    "                relative_path = markdown_file.relative_to(repo_path)\n",
    "                github_url = f\"https://github.com/{repo_owner}/{repo_name}/blob/{git_sha}/{relative_path}\"\n",
    "                yield Document(page_content=f.read(), metadata={\"source\": github_url})\n",
    "\n",
    "sources = get_github_docs(\"yirenlu92\", \"deno-manual-forked\")\n",
    "\n",
    "source_chunks = []\n",
    "splitter = CharacterTextSplitter(separator=\" \", chunk_size=1024, chunk_overlap=0)\n",
    "for source in sources:\n",
    "    for chunk in splitter.split_text(source.page_content):\n",
    "        source_chunks.append(chunk)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Set Up Vector DB\n",
    "\n",
    "Now that we have the documentation content in chunks, let's put all this information in a vector index for easy retrieval."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "import os\n",
    "search_index = Vectara.from_texts(source_chunks, embedding=None)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Set Up LLM Chain with Custom Prompt\n",
    "\n",
    "Next, let's set up a simple LLM chain but give it a custom prompt for blog post generation. Note that the custom prompt is parameterized and takes two inputs: `context`, which will be the documents fetched from the vector search, and `topic`, which is given by the user."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "from langchain.chains import LLMChain\n",
    "prompt_template = \"\"\"Use the context below to write a 400 word blog post about the topic below:\n",
    "    Context: {context}\n",
    "    Topic: {topic}\n",
    "    Blog post:\"\"\"\n",
    "\n",
    "PROMPT = PromptTemplate(\n",
    "    template=prompt_template, input_variables=[\"context\", \"topic\"]\n",
    ")\n",
    "\n",
    "llm = OpenAI(openai_api_key=os.environ['OPENAI_API_KEY'], temperature=0)\n",
    "\n",
    "chain = LLMChain(llm=llm, prompt=PROMPT)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Generate Text\n",
    "\n",
    "Finally, we write a function to apply our inputs to the chain. The function takes an input parameter `topic`. We find the documents in the vector index that correspond to that `topic`, and use them as additional context in our simple LLM chain."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [],
   "source": [
    "def generate_blog_post(topic):\n",
    "    docs = search_index.similarity_search(topic, k=4)\n",
    "    inputs = [{\"context\": doc.page_content, \"topic\": topic} for doc in docs]\n",
    "    print(chain.apply(inputs))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[{'text': '\\n\\nEnvironment variables are a powerful tool for managing configuration settings in your applications. They allow you to store and access values from anywhere in your code, making it easier to keep your codebase organized and maintainable.\\n\\nHowever, there are times when you may want to use environment variables specifically for a single command. This is where shell variables come in. Shell variables are similar to environment variables, but they won\\'t be exported to spawned commands. They are defined with the following syntax:\\n\\n```sh\\nVAR_NAME=value\\n```\\n\\nFor example, if you wanted to use a shell variable instead of an environment variable in a command, you could do something like this:\\n\\n```sh\\nVAR=hello && echo $VAR && deno eval \"console.log(\\'Deno: \\' + Deno.env.get(\\'VAR\\'))\"\\n```\\n\\nThis would output the following:\\n\\n```\\nhello\\nDeno: undefined\\n```\\n\\nShell variables can be useful when you want to re-use a value, but don\\'t want it available in any spawned processes.\\n\\nAnother way to use environment variables is through pipelines. Pipelines provide a way to pipe the'}, {'text': '\\n\\nEnvironment variables are a great way to store and access sensitive information in your applications. They are also useful for configuring applications and managing different environments. In Deno, there are two ways to use environment variables: the built-in `Deno.env` and the `.env` file.\\n\\nThe `Deno.env` is a built-in feature of the Deno runtime that allows you to set and get environment variables. It has getter and setter methods that you can use to access and set environment variables. For example, you can set the `FIREBASE_API_KEY` and `FIREBASE_AUTH_DOMAIN` environment variables like this:\\n\\n```ts\\nDeno.env.set(\"FIREBASE_API_KEY\", \"examplekey123\");\\nDeno.env.set(\"FIREBASE_AUTH_DOMAIN\", \"firebasedomain.com\");\\n\\nconsole.log(Deno.env.get(\"FIREBASE_API_KEY\")); // examplekey123\\nconsole.log(Deno.env.get(\"FIREBASE_AUTH_DOMAIN\")); // firebasedomain'}, {'text': \"\\n\\nEnvironment variables are a powerful tool for managing configuration and settings in your applications. They allow you to store and access values that can be used in your code, and they can be set and changed without having to modify your code.\\n\\nIn Deno, environment variables are defined using the `export` command. For example, to set a variable called `VAR_NAME` to the value `value`, you would use the following command:\\n\\n```sh\\nexport VAR_NAME=value\\n```\\n\\nYou can then access the value of the environment variable in your code using the `Deno.env.get()` method. For example, if you wanted to log the value of the `VAR_NAME` variable, you could use the following code:\\n\\n```js\\nconsole.log(Deno.env.get('VAR_NAME'));\\n```\\n\\nYou can also set environment variables for a single command. To do this, you can list the environment variables before the command, like so:\\n\\n```\\nVAR=hello VAR2=bye deno run main.ts\\n```\\n\\nThis will set the environment variables `VAR` and `V\"}, {'text': \"\\n\\nEnvironment variables are a powerful tool for managing settings and configuration in your applications. They can be used to store information such as user preferences, application settings, and even passwords. In this blog post, we'll discuss how to make Deno scripts executable with a hashbang (shebang).\\n\\nA hashbang is a line of code that is placed at the beginning of a script. It tells the system which interpreter to use when running the script. In the case of Deno, the hashbang should be `#!/usr/bin/env -S deno run --allow-env`. This tells the system to use the Deno interpreter and to allow the script to access environment variables.\\n\\nOnce the hashbang is in place, you may need to give the script execution permissions. On Linux, this can be done with the command `sudo chmod +x hashbang.ts`. After that, you can execute the script by calling it like any other command: `./hashbang.ts`.\\n\\nIn the example program, we give the context permission to access the environment variables and print the Deno installation path. This is done by using the `Deno.env.get()` function, which returns the value of the specified environment\"}]\n"
     ]
    }
   ],
   "source": [
    "generate_blog_post(\"environment variables\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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