Python爬虫之xlml解析库(全面了解)

#!/usr/bin/python#_*_coding:utf-8_*_from lxml import etreetext='''<div> <ul>  <li class="item-0"><a href="link1.html" rel="external nofollow" rel="external nofollow" >first item</a></li>  <li class="item-1"><a href="link2.html" rel="external nofollow" >second item</a></li>  <li class="item-inactive"><a href="link3.html" rel="external nofollow" >third item</a></li>  <li class="item-1"><a href="link4.html" rel="external nofollow" >fourth item</a></li>  <li class="item-0"><a href="link5.html" rel="external nofollow" >fifth item</a> </ul></div>  '''# html=etree.HTML(text) #html对象，存储在地址中，有自动修正功能# result=etree.tostring(html) #将html对象转化为字符串html=etree.parse('hello.html')# result=etree.tostring(html,pretty_print=True)# print resultprint type(html)result= html.xpath('//li')print resultprint len(result)print type(result)print type(result[0])print html.xpath('//li/@class') # 获取li标签下的所有的classprint html.xpath('//li/a[@href="link1.html" rel="external nofollow" rel="external nofollow" ]') #获取li标签下href为link1的<a>标签print html.xpath('//li//span') #获取li标签下所有的span标签print html.xpath('//li[last()-1]/a')[0].text #获取倒数第二个元素的内容