python xpath对孙节点内容进行匹配问题

Question

首先查看节点结构如下，需要获取节点summaryrecordstable下的所有后代节点中，具有数据值id=RECORD_[0-9]的节点

代码如下

import requests
from lxml import etree
 
url_base='https://apps.webofknowledge.com'
url_test='https://apps.webofknowledge.com/full_record.do?product=WOS&search_mode=GeneralSearch&qid=2&SID=6C4xx6Mer35kGYw4PU7&page=1&doc=50'
url_head={
    'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36 Edg/89.0.774.57'
}
session=requests.session();
res=session.get(url_test,headers=url_head)
res_html = etree.HTML(res.text)
url_cited_post=res_html.xpath('//a[@title="View all of the articles that cite this one"]/@href')#如果把@herf替换为text(),获取不到信息,因为a标签只有属性没有文本
print(url_cited_post[0])
url_allcited=url_base+url_cited_post[0]
res=session.get(url_allcited,headers=url_head)
res_html = etree.HTML(res.text)
# url_cited_post=res_html.xpath('//div[contains(@id,"RECORD_")]')
url_cited_post=res_html.xpath('//div[contains(@id,"summaryRecordsTable")]//div[contains(@id,"RECORD_")]')
print('end')
 

倒数第三行，井号注释哪一行可以正常输出，但是加上前缀后，如倒数第二行，就不能正常输出了，不知道是怎么回事

 

Answer 1

用following定位，把前面设为顶节点，following后利用属性值再定位子孙节点。

url_cited_post = res_html.xpath(

    './/div[contains(@id,"summaryRecordsTable")]//following::div[contains(@id,"RECORD_")]')