作者：SeanCheney
链接：https://www.jianshu.com/p/8e5d67ee11a2
來源：简书
Scrapy1.4最新官方文档总结 1 介绍·安装
Scrapy1.4最新官方文档总结 2 Tutorial
Scrapy1.4最新官方文档总结 3 命令行工具
这是官方文档的爬虫https://docs.scrapy.org/en/latest/topics/spiders.html
官方文档给的爬虫的定义：
Spiders are classes which define how a certain site (or a group of sites) will be scraped, including how to perform the crawl (i.e. follow links) and how to extract structured data from their pages (i.e. scraping items). In other words, Spiders are the place where you define the custom behaviour for crawling and parsing pages for a particular site (or, in some cases, a group of sites).
