May 2017
Beginner to intermediate
220 pages
5h 2m
English
Content preview from Python Web Scraping - Second Edition
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Tuning settings
Before running the generated crawl spider, the Scrapy settings should be updated to avoid the spider being blocked. By default, Scrapy allows up to 16 concurrent downloads for a domain with no delay between downloads, which is much faster than a real user would browse. This behavior is easy for a server to detect and block.
As mentioned in Chapter 1, the example website we are scraping is configured to temporarily block crawlers which consistently download at faster than one request per second, so the default settings would ensure our spider is blocked. Unless you are running the example website locally, I recommend adding these lines to example/settings.py so the crawler only downloads a single request per domain at a time ...
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