如何在ElementTree中使用xpath搜索多个属性

Question

我希望从XML文件（https://digitallibrary.un.org/search?ln=en&p=A/RES/72/266&f=&rm=&ln=en&sf=&so=d&rg=50&c=United+Nations+Digital+Library+System&of=xm&fti=0&fti=0）中隔离以下值

<collection>
  <record>
    ...
    <datafield tag="993" ind1="2" ind2=" ">
      <subfield code="a">A/C.5/72/L.22</subfield> # Value to isolate: A/C.5/72/L.22
    </datafield>
    <datafield tag="993" ind1="3" ind2=" ">
      <subfield code="a">A/72/682</subfield> # Value to isolate: A/72/682
    </datafield>
    <datafield tag="993" ind1="4" ind2=" ">
      <subfield code="a">A/72/PV.76</subfield> # Value to isolate: A/72/PV.76
    </datafield>
    ...
  </record>
  <record>
    ...
    <datafield tag="993" ind1="2" ind2=" ">
      <subfield code="a">A/C.5/72/L.22</subfield> # Value to isolate: A/C.5/72/L.22
    </datafield>
    <datafield tag="993" ind1="3" ind2=" ">
      <subfield code="a">A/72/682</subfield> # Value to isolate: A/72/682
    </datafield>
  </record>
  ...
</collection>

我准备的代码似乎只为每条记录标识标记为993的第一项

for record in root:
  if record.find("{http://www.loc.gov/MARC21/slim}datafield[@tag='993']/{http://www.loc.gov/MARC21/slim}subfield[@code='a']") is not None:
    symbol = record.find("{http://www.loc.gov/MARC21/slim}datafield[@tag='993']/{http://www.loc.gov/MARC21/slim}subfield[@code='a']").text
    print symbol

是否有一种使用ElementTree的xpath循环搜索多个属性的方法？先谢谢你

Answer 1

docs显示.find()只获取第一个匹配的子元素。听起来你想要.findall()

以下几点似乎对我有用：

import xml.etree.ElementTree as ET
tree = ET.parse(input_file)
root = tree.getroot()

for record in root:
    xpath = "{http://www.loc.gov/MARC21/slim}datafield[@tag='993']/{http://www.loc.gov/MARC21/slim}subfield[@code='a']"
    if record.findall(xpath) is not None:
        for symbol in record.findall(xpath):
            print symbol.text

Answer 2

要完成用户3091877的回答，请选择其他XPath选项：

//*[name()="subfield"][@code="a"][parent::*[@tag="993"]]/text()

编辑：这个将返回6个值（@tag=993和@ind1=3）：

//*[name()="subfield"][parent::*[@tag="993" and @ind1="3"]]/text()