选择两个节点之间的兄弟姐妹答案

【问题标题】：Select siblings between two nodes选择两个节点之间的兄弟姐妹
【发布时间】：2012-03-28 17:54:43
【问题描述】：

我必须收集所有类别名称以及它们下的所有 div，类以“config-entry”开头。

<h2>category 1</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<h2>category 2</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<h2>category 3</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<h2>category 4</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>

我正在使用 xpath //h2[1]/following-sibling::h2[1]/preceding-sibling::div[starts-with(@class,'config-entry')] 喜欢：

categories = root.xpath("//h2")
for i in xrange(len(categories)):
   print "----%s----" % categories[i].text
   contents = root.xpath("//h2[1]/following-sibling::h2[1]/preceding-sibling::div[starts-with(@class,'config-entry')]")
   print len(contents)

此代码仅适用于类别 1。选择类别 1 和 2 之间的所有 div，但稍后会搞砸。我玩过h2[1]，将其更改为 0,2,3 但没有具体内容。有什么线索吗？

【问题讨论】：

标签： python html xpath

【解决方案1】：

我建议使用 h2 标签和 div 标签的联合，这将按文档顺序返回它们，然后在您处理它们时，每个 div“属于”您看到的最后一个 h2 .

例如

'//h2|//div[contains(@class,"config-entry")]'

工作示例：

from lxml import etree

doc = etree.HTML("""
<html>
<h2>category 1</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<h2>category 2</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<h2>category 3</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<h2>category 4</h2>
<div class='clear10'></div>
<div class='config-entry selected-block'>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
<div class='config-entry '>...</div>
</html>""")

category = None
for ele in doc.xpath('//h2|//div[contains(@class,"config-entry")]'):
  if ele.tag == 'h2':
    category = str(ele.text)
  else:
    if category:
      print "%s: %s, %r" % (category,ele.tag,ele.attrib)

产量：

category 1: div, {'class': 'config-entry selected-block'}
category 1: div, {'class': 'config-entry '}
category 1: div, {'class': 'config-entry '}
category 1: div, {'class': 'config-entry '}
category 2: div, {'class': 'config-entry selected-block'}
category 2: div, {'class': 'config-entry '}
category 2: div, {'class': 'config-entry '}
category 2: div, {'class': 'config-entry '}
category 2: div, {'class': 'config-entry '}
category 3: div, {'class': 'config-entry selected-block'}
category 3: div, {'class': 'config-entry '}
category 4: div, {'class': 'config-entry selected-block'}
category 4: div, {'class': 'config-entry '}
category 4: div, {'class': 'config-entry '}
category 4: div, {'class': 'config-entry '}

【讨论】：