Python - 使用属性解析 XML 树答案

【问题标题】：Python - Using attributes to parse XML treePython - 使用属性解析 XML 树
【发布时间】：2017-06-08 21:52:53
【问题描述】：

有很多关于如何使用树中的标签解析 XML 的示例，但是如果（如下例所示）许多标签具有相同的名称怎么办？

<SoccerFeed timestamp="20161221T144346+0000">
  <SoccerDocument Type="SQUADS Latest">
    <Team country="USA">
      <Founded>1998</Founded>
      <Name>Chicago Fire</Name>
      <Player uID="p113757">
        <Name>Patrick McLain</Name>
        <Position>Goalkeeper</Position>
        <Stat Type="first_name">Patrick</Stat>
        <Stat Type="last_name">McLain</Stat>
        <Stat Type="birth_date">1988-08-22</Stat>
        <Stat Type="birth_place">Eau Claire</Stat>
        <Stat Type="first_nationality">USA</Stat>
        <Stat Type="weight">94</Stat>
        <Stat Type="height">191</Stat>
        <Stat Type="jersey_num">23</Stat>
        <Stat Type="real_position">Goalkeeper</Stat>
        <Stat Type="real_position_side">Unknown</Stat>
        <Stat Type="join_date">2016-01-18</Stat>
        <Stat Type="country">USA</Stat>
      </Player>
    </Team>
  </SoccerDocument>
</SoccerFeed>

如果我只想解析带有“Stat”标签和“first_name”属性的元素，我该怎么做？

【问题讨论】：

标签： python r lxml elementtree

【解决方案1】：

使用 R 和 xml2 库：

library("xml2")
myxml<-read_xml('<SoccerFeed timestamp="20161221T144346+0000">
<SoccerDocument Type="SQUADS Latest">
<Team country="USA">
<Founded>1998</Founded>
<Name>Chicago Fire</Name>
<Player uID="p113757">
<Name>Patrick McLain</Name>
<Position>Goalkeeper</Position>
<Stat Type="first_name">Patrick</Stat>
<Stat Type="last_name">McLain</Stat>
<Stat Type="birth_date">1988-08-22</Stat>
<Stat Type="birth_place">Eau Claire</Stat>
<Stat Type="first_nationality">USA</Stat>
<Stat Type="weight">94</Stat>
<Stat Type="height">191</Stat>
<Stat Type="jersey_num">23</Stat>
<Stat Type="real_position">Goalkeeper</Stat>
<Stat Type="real_position_side">Unknown</Stat>
<Stat Type="join_date">2016-01-18</Stat>
<Stat Type="country">USA</Stat>
</Player>
</Team>
</SoccerDocument>
</SoccerFeed>')

#get all of the Stat nodes
statnodes<-xml_nodes(myxml, "Stat")
#filter for first_name node
firstname<- statnodes[xml_attr(statnodes, "Type" )== "first_name"]
#get text value
xml_text(firstname)

【讨论】：

【解决方案2】：

您可以在XML 解析器中使用BeautifulSoup，如下例所示：

from bs4 import BeautifulSoup as bs

data = '''<SoccerFeed timestamp="20161221T144346+0000">
  <SoccerDocument Type="SQUADS Latest">
    <Team country="USA">
      <Founded>1998</Founded>
      <Name>Chicago Fire</Name>
      <Player uID="p113757">
        <Name>Patrick McLain</Name>
        <Position>Goalkeeper</Position>
        <Stat Type="first_name">Patrick</Stat>
        <Stat Type="last_name">McLain</Stat>
        <Stat Type="birth_date">1988-08-22</Stat>
        <Stat Type="birth_place">Eau Claire</Stat>
        <Stat Type="first_nationality">USA</Stat>
        <Stat Type="weight">94</Stat>
        <Stat Type="height">191</Stat>
        <Stat Type="jersey_num">23</Stat>
        <Stat Type="real_position">Goalkeeper</Stat>
        <Stat Type="real_position_side">Unknown</Stat>
        <Stat Type="join_date">2016-01-18</Stat>
        <Stat Type="country">USA</Stat>
      </Player>
    </Team>
  </SoccerDocument>
</SoccerFeed>'''

sub = bs(data, 'xml')
# Find all the 'Stat' tags
stat_tags = sub.findAll('Stat')
for k in stat_tags:
    # Extract the text between 'Stat' tags
    print(k.text)

输出：

Patrick
McLain
1988-08-22
Eau Claire
USA
94
191
23
Goalkeeper
Unknown
2016-01-18
USA

【讨论】：

【解决方案3】：

使用 ElementTree：

for firstnames in root.findall('Team/Player/Stat[@type="first_name"]')
    print(firstnames.attrib)

完整的 XPath 语法：https://docs.python.org/3.6/library/xml.etree.elementtree.html#supported-xpath-syntax

【讨论】：