此片段来自您的问题，

for a in root.findall('{urn:com:xml:data}image'):
    print a.attrib

不输出任何内容，因为它只查找直接的 {urn：com：xml：data}图像树根的子代。

does not output anything because it only looks for direct {urn:com:xml:data}image children of the root of the tree.

此代码稍作修改，

for a in root.findall('.//{urn:com:xml:data}image'):
    print a.attrib

将打印 {'imageId'：'1'} ，因为它使用的是。/ / ，它会在所有级别上选择匹配的子元素。

will print {'imageId': '1'} because it uses .//, which selects matching subelements on all levels.

参考： https://docs.python.org/2/library/xml.etree.elementtree.html#supported-xpath-syntax 。

令人讨厌的是，ElementTree不仅保留了默认情况下是原始名称空间前缀，但请记住，无论如何前缀都不重要。 register_namespace（）函数可用于在对XML进行序列化时设置所需的前缀。该功能对解析或搜索没有任何影响。

It is a bit annoying that ElementTree does not just retain the original namespace prefixes by default, but keep in mind that it is not the prefixes that matter anyway. The register_namespace() function can be used to set the wanted prefix when serializing the XML. The function does not have any effect on parsing or searching.