Python xml.dom中没有递归（单节点级别）getElementsByTagName

Question

Is there any way to use getElementsByTagName only at a single node level and not recursively?

Eg consider parsing a pom.xml file:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <parent>
        <groupId>com.parent</groupId>
        <artifactId>parent</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>

    <modelVersion>2.0.0</modelVersion>
    <groupId>com.parent.somemodule</groupId>
    <artifactId>some_module</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Some Module</name>
    ...

If I want to get groupId at the top level (specifically project->groupId , not project->parent->groupId ), I use:

xmldoc = minidom.parse('pom.xml')
groupId = xmldoc.getElementsByTagName("groupId")[0].childNodes[0].nodeValue

But unfortunately, that finds the first physical occurrence of groupId in the file regardless of the hierarchy level, which is project->parent->groupId . I actually want to do a unrecursive find ONLY at a specific node level, not within its children. Is there a way to do it in xml.dom ?

UPDATE: I switched to BeautifulSoup but still having the same problem with implicit recursive traversing: Finding a nonrecursive DOM subnode in Python using BeautifulSoup

Answer 1

You can iterate over getElementsByTagName() results and take the first element that is in on the root level:

group_id_element =  next(element for element in xmldoc.getElementsByTagName("groupId")
                         if element.parentNode == xmldoc.documentElement)

print group_id_element.childNodes[0].nodeValue

Note that it would be easier, shorter and faster to do the same with ElementTree , which is also a part of standard library.

Hope that helps.