如果语句不能在ElementTree解析中工作，为什么会这样？

Abhishek 发表于 Dev

阿比舍克

我正在尝试xml使用如下ElementTree形式解析文件：

<Game>
  <Event timestamp="2016-08-14T14:23:33.634" id="1713385925" 
         version="1471181110290" last_modified="2016-08-14T14:25:11" y="11.0" 
         x="89.7" outcome="0" team_id="148" player_id="51327" sec="8" min="23" 
         period_id="1" type_id="4" event_id="205">

    <Q id="733814222" qualifier_id="265"/>
    <Q id="481660420" qualifier_id="286"/>
    <Q id="813378778" qualifier_id="152"/>
    <Q id="570443899" qualifier_id="56" value="Right"/>
    <Q id="420312891" qualifier_id="233" value="248"/>
    <Q id="1186861264" qualifier_id="13"/>
  </Event>

  <Event timestamp="2016-08-14T14:23:33.634" id="1635888622" 
         version="1471181110289" last_modified="2016-08-14T14:25:11" y="89.0" 
         x="10.3" outcome="1" team_id="143" player_id="169007" sec="8" min="23" 
         period_id="1" type_id="4" event_id="248">

    <Q id="1871787686" qualifier_id="56" value="Back"/>
    <Q id="176295814" qualifier_id="13"/>
    <Q id="69346842" qualifier_id="233" value="205"/>
    <Q id="1588029344" qualifier_id="265"/>
    <Q id="559785299" qualifier_id="285"/>
    <Q id="380723313" qualifier_id="152"/>
  </Event>
</Game>

我正在使用的代码很简单，并且可以按预期工作。但是，当我尝试向if condition代码中添加时，一切都会改变

import xml.etree.ElementTree as ET

root = ET.parse(r'C:\Users\ADMIN\Desktop\Abhishek\PSG - Copy\Sample.xml').getroot()

Games = root.getchildren()
for Game in Games:
    Events = Game.getchildren()
    for Event in Events:
        type_id = Event.attrib["type_id"]
        team_id = Event.attrib["team_id"]
        Qualifiers = Event.getchildren()
        for Qualifier in Qualifiers:
            id_ = Qualifier.attrib['id']
            if id_ == 142:
                print ("val")

这是它产生的错误：

Warning (from warnings module):
  File "C:\Users\ADMIN\AppData\Local\Programs\Python\Python37\PSGPossessionSequences.py", line 9
    Games = root.getchildren()
DeprecationWarning: This method will be removed in future versions.  Use 'list(elem)' or iteration over elem instead.

Warning (from warnings module):
  File "C:\Users\ADMIN\AppData\Local\Programs\Python\Python37\PSGPossessionSequences.py", line 11
    Events = Game.getchildren()
DeprecationWarning: This method will be removed in future versions.  Use 'list(elem)' or iteration over elem instead.

Warning (from warnings module):
  File "C:\Users\ADMIN\AppData\Local\Programs\Python\Python37\PSGPossessionSequences.py", line 15
    Qualifiers = Event.getchildren()
DeprecationWarning: This method will be removed in future versions.  Use 'list(elem)' or iteration over elem instead.

我试着删除，if statement并且效果很好。但是，我确实需要设置一个条件来调用所有id_具有确定值的。我尝试使用"142"以及，142但问题仍然存在。为什么会这样呢？

马丁·彼得斯（Martijn Pieters）

您看到的错误不是错误，而是警告。您可以不使用它们而忽略它们，或者使它们静默或修复代码.get_children()。您可以直接在每个XML元素上进行迭代：

root = ET.parse(r'C:\Users\ADMIN\Desktop\Abhishek\PSG - Copy\Sample.xml').getroot()

for Game in root:
    for Event in Game:
        # ...
        for Qualifier in Event:

该if测试不起作用，因为XML属性是字符串，文本而不是整数值。测试字符串：

if id_ == "142":
    print("val")

您可能要使用XPath查询，而不是遍历所有内容。但是，Python随附的基本ElementTree实现受到一些限制。如果安装了lxml库，您将获得更强大的实现，它对XPath的支持要优越得多：

from lxml import etree as ET

document = ET.parse(r'C:\Users\ADMIN\Desktop\Abhishek\PSG - Copy\Sample.xml')
root = document.getroot()

qualifier = root.xpath(".//Event/Q[@id='142']")[0]
event = qualifier.getparent()
type_id = event.attrib["type_id"]
team_id = event.attrib["team_id"]

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