xpath剔除某些不需要的资源/元素:
html.xpath("//h1[@name='hname' and not(contains(@class,'cname2'))]//text()")
//span[starts-with(@id,'nothread')]/following::*[1][name()='blockquote']/text()
// DIV [@类=“ipsType_normal ipsType_richText ipsContained “]/p [not(@ class =”ipsQuote“)]
html.xpath('/html/body/*[not(name()="form")]//text()')