February 2018
Beginner to intermediate
364 pages
10h 32m
English
Content preview from Python Web Scraping Cookbook
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Crawling with delays
Fast scraping is considered a bad practice. Continuously pounding a website for pages can burn up CPU and bandwidth, and a robust site will identify you doing this and block your IP. And if you are unlucky, you might get a nasty letter for violating terms of service!
The technique of delaying requests in your crawler depends upon how your crawler is implemented. If you are using Scrapy, then you can set a parameter that informs the crawler how long to wait between requests. In a simple crawler just sequentially processing URLs in a list, you can insert a thread.sleep statement.
Things can get more complicated if you have implemented a distributed cluster of crawlers that spread the load of page requests, such as using ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.