连接SQLite 要操作关系数据库，首先需要连接到数据库，一个数据库连接称为Connection； 连接到数据库后，需要打开游标，称之为Curs

Scrapy is a fast high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages. It can be used for a wide range of purposes, from data mining to monitoring and automated testing. ​ ———来自官方文档的介