WebPDFLoader

此笔记本提供了有关如何开始使用 WebPDFLoader 的快速概述。有关所有 WebPDFLoader 功能和配置的详细文档，请前往 API 参考。

概述

集成详细信息

类	包	本地	可序列化	PY 支持
WebPDFLoader	@langchain/community	✅	测试版	❌

加载器功能

来源	网络加载器	仅限节点环境
WebPDFLoader	✅	❌

您可以在网络环境中使用此版本的流行 PDFLoader。默认情况下，将为 PDF 文件中的每个页面创建一个文档，您可以通过将 splitPages 选项设置为 false 来更改此行为。

设置

要访问 WebPDFLoader 文档加载器，您需要安装 @langchain/community 集成以及 pdf-parse 包

凭据

如果您想获取模型调用的自动跟踪，您还可以通过取消以下注释来设置您的 LangSmith API 密钥

# export LANGCHAIN_TRACING_V2="true"
# export LANGCHAIN_API_KEY="your-api-key"

安装

LangChain WebPDFLoader 集成位于 @langchain/community 包中

提示

查看 此部分，了解有关安装集成包的通用说明。

npm

npm i @langchain/community @langchain/core pdf-parse

yarn

yarn add @langchain/community @langchain/core pdf-parse

pnpm

pnpm add @langchain/community @langchain/core pdf-parse

实例化

现在我们可以实例化我们的模型对象并加载文档

import fs from "fs/promises";
import { WebPDFLoader } from "@langchain/community/document_loaders/web/pdf";

const nike10kPDFPath = "../../../../data/nke-10k-2023.pdf";

// Read the file as a buffer
const buffer = await fs.readFile(nike10kPDFPath);

// Create a Blob from the buffer
const nike10kPDFBlob = new Blob([buffer], { type: "application/pdf" });

const loader = new WebPDFLoader(nike10kPDFBlob, {
  // required params = ...
  // optional params = ...
});

加载

const docs = await loader.load();
docs[0];

Document {
  pageContent: 'Table of Contents\n' +
    'UNITED STATES\n' +
    'SECURITIES AND EXCHANGE COMMISSION\n' +
    'Washington, D.C. 20549\n' +
    'FORM 10-K\n' +
    '(Mark One)\n' +
    '☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934\n' +
    'FOR THE FISCAL YEAR ENDED MAY 31, 2023\n' +
    'OR\n' +
    '☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934\n' +
    'FOR THE TRANSITION PERIOD FROM                         TO                         .\n' +
    'Commission File No. 1-10635\n' +
    'NIKE, Inc.\n' +
    '(Exact name of Registrant as specified in its charter)\n' +
    'Oregon93-0584541\n' +
    '(State or other jurisdiction of incorporation)(IRS Employer Identification No.)\n' +
    'One Bowerman Drive, Beaverton, Oregon 97005-6453\n' +
    '(Address of principal executive offices and zip code)\n' +
    '(503) 671-6453\n' +
    "(Registrant's telephone number, including area code)\n" +
    'SECURITIES REGISTERED PURSUANT TO SECTION 12(B) OF THE ACT:\n' +
    'Class B Common StockNKENew York Stock Exchange\n' +
    '(Title of each class)(Trading symbol)(Name of each exchange on which registered)\n' +
    'SECURITIES REGISTERED PURSUANT TO SECTION 12(G) OF THE ACT:\n' +
    'NONE\n' +
    'Indicate by check mark:YESNO\n' +
    '•if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.þ ̈\n' +
    '•if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. ̈þ\n' +
    '•whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding\n' +
    '12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the\n' +
    'past 90 days.\n' +
    'þ ̈\n' +
    '•whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T\n' +
    '(§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).\n' +
    'þ ̈\n' +
    '•whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,”\n' +
    '“accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.\n' +
    'Large accelerated filerþAccelerated filer☐Non-accelerated filer☐Smaller reporting company☐Emerging growth company☐\n' +
    '•if an emerging growth company, if the registrant has elected not to use the extended transition period for complying with any new or revised financial\n' +
    'accounting standards provided pursuant to Section 13(a) of the Exchange Act.\n' +
    ' ̈\n' +
    "•whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial\n" +
    'reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit\n' +
    'report.\n' +
    'þ\n' +
    '•if securities are registered pursuant to Section 12(b) of the Act, whether the financial statements of the registrant included in the filing reflect the\n' +
    'correction of an error to previously issued financial statements.\n' +
    ' ̈\n' +
    '•whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the\n' +
    "registrant's executive officers during the relevant recovery period pursuant to § 240.10D-1(b).\n" +
    ' ̈\n' +
    '•\n' +
    'whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).☐þ\n' +
    "As of November 30, 2022, the aggregate market values of the Registrant's Common Stock held by non-affiliates were:\n" +
    'Class A$7,831,564,572 \n' +
    'Class B136,467,702,472 \n' +
    '$144,299,267,044 ',
  metadata: {
    pdf: {
      version: '1.10.100',
      info: [Object],
      metadata: null,
      totalPages: 107
    },
    loc: { pageNumber: 1 }
  },
  id: undefined
}

console.log(docs[0].metadata);

{
  pdf: {
    version: '1.10.100',
    info: {
      PDFFormatVersion: '1.4',
      IsAcroFormPresent: false,
      IsXFAPresent: false,
      Title: '0000320187-23-000039',
      Author: 'EDGAR Online, a division of Donnelley Financial Solutions',
      Subject: 'Form 10-K filed on 2023-07-20 for the period ending 2023-05-31',
      Keywords: '0000320187-23-000039; ; 10-K',
      Creator: 'EDGAR Filing HTML Converter',
      Producer: 'EDGRpdf Service w/ EO.Pdf 22.0.40.0',
      CreationDate: "D:20230720162200-04'00'",
      ModDate: "D:20230720162208-04'00'"
    },
    metadata: null,
    totalPages: 107
  },
  loc: { pageNumber: 1 }
}

用法，自定义 pdfjs 构建

默认情况下，我们使用与 pdf-parse 捆绑在一起的 pdfjs 构建，该构建与大多数环境兼容，包括 Node.js 和现代浏览器。如果您想使用更新版本的 pdfjs-dist 或如果您想使用 pdfjs-dist 的自定义构建，您可以通过提供一个自定义 pdfjs 函数来实现，该函数返回一个解析为 PDFJS 对象的承诺。

在以下示例中，我们使用 pdfjs-dist 的“传统”（请参阅 pdfjs 文档）构建，其中包含默认构建中未包含的几个垫片。

npm

npm i pdfjs-dist

yarn

yarn add pdfjs-dist

pnpm

pnpm add pdfjs-dist

import { WebPDFLoader } from "@langchain/community/document_loaders/web/pdf";

const blob = new Blob(); // e.g. from a file input

const customBuildLoader = new WebPDFLoader(blob, {
  // you may need to add `.then(m => m.default)` to the end of the import
  pdfjs: () => import("pdfjs-dist/legacy/build/pdf.js"),
});

消除额外的空格

PDF 有很多种，这使得阅读它们成为一项挑战。加载器默认情况下会解析各个文本元素并将它们与一个空格连接在一起，但如果您看到过多的空格，这可能不是您想要的。在这种情况下，您可以使用空字符串覆盖分隔符，如下所示

import { WebPDFLoader } from "@langchain/community/document_loaders/web/pdf";

// new Blob(); e.g. from a file input
const eliminatingExtraSpacesLoader = new WebPDFLoader(new Blob(), {
  parsedItemSeparator: "",
});

API 参考

有关所有 WebPDFLoader 功能和配置的详细文档，请前往 API 参考：https://api.js.langchain.com/classes/langchain_community_document_loaders_web_pdf.WebPDFLoader.html