python - lxml中xpath获取本节点及以下所有节点的text()方法？

Question

<ul id="parameter2" class="p-parameter-list">
 <li title='养生堂天然维生素E软胶囊'>商品名称：养生堂天然维生素E软胶囊</li>
 <li title='720135'>商品编号：720135</li>
 <li title='养生堂'>品牌：<a>养生堂</a></li>
</ul>

以上是网页源码，现通过xpath匹配所有Li

import lxml.etree as etree
html = html.decode("utf-8")
tree = etree.HTML(html)
property_list_reg = "//ul[@id='parameter2']/li/text()"
property_lst = tree.xpath(property_list_reg)
print len(property_lst)   

输出结果：

3
商品名称：养生堂天然维生素E软胶囊
商品编号：720135
品牌：

如果换成：

property_list_reg = "//ul[@id='parameter2']/li//text()" #此处//

输出结果：

4
商品名称：养生堂天然维生素E软胶囊
商品编号：720135
品牌：
养生堂

显然，这不是我想要的结果，我想要的结果是这样

3
商品名称：养生堂天然维生素E软胶囊
商品编号：720135
品牌： 养生堂

求大神指导~ 该如何实现？

Answer 1

The correct way is to use Xpath’s string function

import lxml.etree as etree
html = """
<ul id="parameter2" class="p-parameter-list">
 <li title='养生堂天然维生素E软胶囊'>商品名称：养生堂天然维生素E软胶囊</li>
 <li title='720135'>商品编号：720135</li>
 <li title='养生堂'>品牌：<a>养生堂</a></li>
</ul>
"""
tree = etree.HTML(html)
property_list_reg = '//ul[@id="parameter2"]//li'
property_lst = tree.xpath(property_list_reg)
for e in property_lst:
    print(e.xpath('string(.)'))
print(len(property_lst))

Answer 2

In the definition of XPath, "//" is "/descendant-or-self::node()/", indicating the matching of the current node or descendant node, so you use "//text()" to confirm It will match the child nodes below. A clearer way is to match the li layer of the parent node and then manually process the child nodes.

html = """
<ul id="parameter2" class="p-parameter-list">
 <li title='养生堂天然维生素E软胶囊'>商品名称：养生堂天然维生素E软胶囊</li>
 <li title='720135'>商品编号：720135</li>
 <li title='养生堂'>品牌：<a>养生堂</a></li>
</ul>
"""

html = html.decode("utf-8")
tree = etree.HTML(html)

property_list_reg = '//ul[@id="parameter2"]/li'


def tryFindChild(element):
    children = element.getchildren()
    if len(children):
        return element.text + " " + children[0].text
    else:
        return element.text


property_lst = tree.xpath(property_list_reg)
for e in property_lst:
    print tryFindChild(e)

print len(property_lst)

Output
Product name: Yangshengtang Natural Vitamin E Soft Capsule
Product number: 720135
Brand: Yangshengtang
3