核心提示:#coding:utf8# BeautifulSoup可以将lxml作为默认的解析器使用,lxml亦可以单独使用;# 比较BeautifulSoup和lxml:#(1)#BeaufulSoup基于DO...
#coding:utf8 # BeautifulSoup可以将lxml作为默认的解析器使用,lxml亦可以单独使用; # 比较BeautifulSoup和lxml: #(1) #BeaufulSoup基于DOM,会在如整个文档,解析整个DOM树,比较消耗内存和时间; #lxml是使用XPath技术查询和处理HTML/XML文档库,只会局部遍历,所以速度较快。 #现在BeautifulSoup可以使用lxml作为默认解析库’ #(2) #BeautifulSoup较简单,API非常人性化,支持CSS选择器。 # lxml的XPath比较麻烦,开发效率不如BeautifulSoup #使用lxml解析网页,实例: from lxml import etree html_str = """
The Dormouse's story
Once upon a time there were three little sisters; and their names were , and Tillie; and they lived at the bottom of a well.
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""" html = etree.HTML(html_str) result = etree.tostring(html) print result #lxml还可以自动修正html代码 #除了读取字符串之外,lxml还可以直接读取html文件 #将html_str存储为index.html文件,理由parse方法进行解析: from lxml import etree html = etree.parse('index.html') result = etree.tostring(html, pretty_print=True) print result #用XPath语法抽取所有的URL: html = etree.HTML(html_str) urls = html.xpath(".//*[@class='sister']/@href") print urls