在SelectSingleNode上使用Python解析XML

Question

使用以下XML數據我想獲取我通過Python代碼調用的相關鍵的值。我想在不使用任何第三方庫的情況下完成此任務。

<Userinfo> 
    <UserData> 
    <item key="DateOfBirth" value="19851103" /> 
    <item key="FirstName" value="John" /> 
    <item key="LastName" value="Dicaprio" /> 
    <item key="Gender" value="M" /> 
    <item key="Email" value="john@abc.com" /> 
    <item key="ContactNo" value="235625341" /> 
    </UserData> 
</Userinfo> 

從上面的xml代碼中，我想從我在下面的python代碼中調用的鍵中提取值。

def ExtractXml(args): 
url = '....' 
wc = System.Net.WebClient() 
xml = wc.DownloadString(url) 
doc = System.Xml.XmlDocument() 
doc.LoadXml(xml) 
root = doc.DocumentElement 
nsmgr = System.Xml.XmlNamespaceManager(doc.NameTable) 
#nsmgr.AddNamespace('ns','http://schemas.microsoft.com/developer/msbuild/2003') 
node = root.SelectNodes('/Userinfo/UserData',nsmgr) 
tcount=root.SelectNodes('/Userinfo/UserData').Count 

if not node: 
    ServiceDesk.Log.PrintError('No condition node') 
    return 

r=[] 
t={} 

counts=0 
for itemNode in node: 
    counts += 1 
    fullname = xstr(itemNode.SelectSingleNode("/item[@key='FirstName']/@value",nsmgr)) 
    empname = xstr(itemNode.SelectSingleNode("/item[@key='LastName']/@value",nsmgr)) 
    cardcountry = xstr(itemNode.SelectSingleNode("/item[@key='Email']/@value",nsmgr)) 
    #birthdate = ServiceDesk.Common.ParseDateTime(itemNode.SelectSingleNode("item[@key='DateOfBirth']")) 

    t = {'counter':counts,'FirstName':fullname,'LastName':empname,'Email':cardcountry,'__rowid__':counter,'__totalcount__':tcount} 
    r.append(t) 
return r 

使用以下代碼，它不會檢索SelectSingleNode調用上相關鍵的值。提前致謝。

Answer 1

我不太確定IronPython，但是Python的核心庫包含一些其他獨立於平臺的XML解析器......以下是一個使用xml.etree.ElementTree的示例。

import datetime 
import xml.etree.ElementTree as ET 

xml = '''<Userinfo> 
    <UserData> 
     <item key="DateOfBirth" value="19851103" /> 
     <item key="FirstName" value="John" /> 
     <item key="LastName" value="Dicaprio" /> 
     <item key="Gender" value="M" /> 
     <item key="Email" value="john@abc.com" /> 
     <item key="ContactNo" value="235625341" /> 
    </UserData> 
</Userinfo>''' 

root = ET.fromstring(xml) 
fname = root.findall(".//item[@key='FirstName']")[0].get('value') 
dob = datetime.datetime.strptime(
     root.findall(".//item[@key='DateOfBirth']")[0].get('value'), 
     '%Y%m%d') 

Answer 2

目前在for循環的XPath表達式都是相對於文檔節點，因爲它開始與/。爲了使它相對於上下文元素，在這種情況下是由itemNode引用，您可以添加前面的.或只是刪除/完全：

for itemNode in node: 
    counts += 1 
    # here are some ways to make your XPath heeds the context element `itemNode` 
    fullname = xstr(itemNode.SelectSingleNode("./item[@key='FirstName']/@value",nsmgr)) 
    empname = xstr(itemNode.SelectSingleNode("item[@key='LastName']/@value",nsmgr)) 
    cardcountry = xstr(itemNode.SelectSingleNode("self::*/item[@key='Email']/@value",nsmgr))