Book Image

Python Web Scraping - Second Edition

By : Katharine Jarmul
Book Image

Python Web Scraping - Second Edition

By: Katharine Jarmul

Overview of this book

The Internet contains the most useful set of data ever assembled, most of which is publicly accessible for free. However, this data is not easily usable. It is embedded within the structure and style of websites and needs to be carefully extracted. Web scraping is becoming increasingly useful as a means to gather and make sense of the wealth of information available online. This book is the ultimate guide to using the latest features of Python 3.x to scrape data from websites. In the early chapters, you'll see how to extract data from static web pages. You'll learn to use caching with databases and files to save time and manage the load on servers. After covering the basics, you'll get hands-on practice building a more sophisticated crawler using browsers, crawlers, and concurrent scrapers. You'll determine when and how to scrape data from a JavaScript-dependent website using PyQt and Selenium. You'll get a better understanding of how to submit forms on complex websites protected by CAPTCHA. You'll find out how to automate these actions with Python packages such as mechanize. You'll also learn how to create class-based scrapers with Scrapy libraries and implement your learning on real websites. By the end of the book, you will have explored testing websites with scrapers, remote scraping, best practices, working with images, and many other relevant topics.
Table of Contents (10 chapters)

Facebook

To demonstrate using a browser and API, we will investigate Facebook's site. Currently, Facebook is the world's largest social network in terms of monthly active users, and therefore, its user data is extremely valuable.

The website

Here is an example Facebook page for Packt Publishing athttps://www.facebook.com/PacktPub:

Viewing the source of this page, you would find that the first few posts are available, and that later posts are loaded with AJAX when the browser scrolls. Facebook also has a mobile interface, which, as mentioned in Chapter 1, Introduction to Web Scraping, is often easier to scrape. The same page using the mobile interface is available at https://m.facebook.com/PacktPub:

If we interacted with the mobile website and then checked...