There are several ways to crawl the crawler,Regular Expressions, Lxml (XPath) and beautiful,I looked up the information on the Internet, to understand the use of the difficulty and performance of the threeThree ways to compare reptiles.
First, select the nodeCommon Road-strength Expressions:
An expression
Describe
Instance
NodeName
Select all child nodes of the NodeName node
XPath ('//div ')
All child nodes of a div node
First, select the nodeCommon Road-strength Expressions:
An expression
Describe
Instance
NodeName
Select all child nodes of the NodeName node
XPath ('//div ')
All child nodes of a div node
Original: Http://ejohn.org/blog/xpath-css-selectors
Lately, I've done a lot of work to implement a parser that supports both XPath and CSS 3, and what surprises me is that they are very similar in some ways, but in other ways they are
Turn from: http://www.cnblogs.com/qingchunjun/p/4208159.html
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