【scrapy】相关

http://www.cnblogs.com/mophee/archive/2009/03/12/1409562.html

css选择器中的空格

http://www.crummy.com/software/BeautifulSoup/bs4/doc/

beautifulsoup4

http://www.zvon.org/comp/r/tut-XPath_1.html#Pages~List_of_XPaths

xpath