Book Image

Go Web Scraping Quick Start Guide

By : Vincent Smith
Book Image

Go Web Scraping Quick Start Guide

By: Vincent Smith

Overview of this book

Web scraping is the process of extracting information from the web using various tools that perform scraping and crawling. Go is emerging as the language of choice for scraping using a variety of libraries. This book will quickly explain to you, how to scrape data data from various websites using Go libraries such as Colly and Goquery. The book starts with an introduction to the use cases of building a web scraper and the main features of the Go programming language, along with setting up a Go environment. It then moves on to HTTP requests and responses and talks about how Go handles them. You will also learn about a number of basic web scraping etiquettes. You will be taught how to navigate through a website, using a breadth-first and then a depth-first search, as well as find and follow links. You will get to know about the ways to track history in order to avoid loops and to protect your web scraper using proxies. Finally the book will cover the Go concurrency model, and how to run scrapers in parallel, along with large-scale distributed web scraping.
Table of Contents (10 chapters)

To get the most out of this book

In order to get the most from this book, you should familiarize yourself with your Terminal or Command Prompt, ensure you have a good internet connection, and read each chapter, even if you think you already know it. The readers of this book should keep an open mind as to how they think a web scraper should act, and they should learn the current best practices and proper etiquette. This book also focuses on the Go programming language, covering the installation, basic commands, the standard library, and package management, so some familiarity with Go will be helpful as this book covers the language in a broad sense and only goes into the depth that is needed for web scraping. To be able to run most of the code in this book, the reader should be familiar with their Terminal or Command Prompt in order to run the examples, among other tasks.

Download the example code files

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

  1. Log in or register at www.packt.com
  2. Select the SUPPORT tab
  3. Click on Code Downloads & Errata
  4. Enter the name of the book in the Search box and follow the onscreen instructions

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

  • WinRAR/7-Zip for Windows
  • Zipeg/iZip/UnRarX for Mac
  • 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Go-Web-Scraping-Quick-Start-Guide. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "This is using the net/http package's default HTTP client to request the index.html resource."

A block of code is set as follows:

POST /login HTTP/1.1
Host: myprotectedsite.com
Content-Type: application/x-www-form-urlencoded
Content-Length: 38

username=myuser&password=supersecretpw

Any command-line input or output is written as follows:

go run main.go

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "In this case, you will receive a status code of 500 Internal Server Error."

Warnings or important notes appear like this.
Tips and tricks appear like this.