E.g. consider parsing a pom.xml file:

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

com.parent

parent

1.0-SNAPSHOT

../pom.xml

2.0.0

com.parent.somemodule

some_module

jar

1.0-SNAPSHOT

Some Module

...

Code:

import xml.etree.ElementTree as ET

tree = ET.parse(pom)

root = tree.getroot()

groupId = root.find("groupId")

artifactId = root.find("artifactId")

Both groupId and artifactId are None. Why when they are the direct descendants of the root? I tried to replace the root with tree (groupId = tree.find("groupId")) but that didn't change anything.

解决方案

The problem is that you don't have a child named groupId, you have a child named {http://maven.apache.org/POM/4.0.0}groupId, because etree doesn't ignore XML namespaces, it uses "universal names". See Working with Namespaces and Qualified Names in the effbot docs.