Python:使用 ElementTree 更新 XML 文件，同时尽可能地保留布局

我有一个使用 XML 命名空间的文档，我想将其 /group/house/dogs 增加一:(文件名为 houses.xml)

I have a document which uses an XML namespace for which I want to increase /group/house/dogs by one: (the file is called houses.xml)

<?xml version="1.0"?>
<group xmlns="http://dogs.house.local">
    <house>
            <id>2821</id>
            <dogs>2</dogs>
    </house>
</group>

我当前使用以下代码的结果是:(创建的文件名为houses2.xml)

My current result using the code below is: (the created file is called houses2.xml)

<ns0:group xmlns:ns0="http://dogs.house.local">
    <ns0:house>
        <ns0:id>2821</ns0:id>
        <ns0:dogs>3</ns0:dogs>
    </ns0:house>
</ns0:group>

我想解决两件事(如果可以使用 ElementTree.如果不是，我很乐意提供关于我应该使用什么的建议):

I would like to fix two things (if it is possible using ElementTree. If it isn´t, I´d be greatful for a suggestion as to what I should use instead):

1. 我想保留 行.
2. 我不想为所有标签添加前缀，我想保持原样.

总而言之，我不想过多地弄乱文档.

我当前的代码(除了上述缺陷外都有效)生成上述结果如下.

My current code (which works except for the above mentioned flaws) generating the above result follows.

我制作了一个实用函数，它使用 ElementTree 加载一个 XML 文件并返回 elementTree 和命名空间(因为我不想对命名空间进行硬编码，并且愿意承担它所暗示的风险):

I have made a utility function which loads an XML file using ElementTree and returns the elementTree and the namespace (as I do not want to hard code the namespace, and am willing to take the risk it implies):

def elementTreeRootAndNamespace(xml_file):
    from xml.etree import ElementTree
    import re
    element_tree = ElementTree.parse(xml_file)

    # Search for a namespace on the root tag
    namespace_search = re.search('^({\S+})', element_tree.getroot().tag)
    # Keep the namespace empty if none exists, if a namespace exists set
    # namespace to {namespacename}
    namespace = ''
    if namespace_search:
        namespace = namespace_search.group(1)

    return element_tree, namespace

这是我更新狗的数量并将其保存到新文件houses2.xml的代码:

This is my code to update the number of dogs and save it to the new file houses2.xml:

elementTree, namespace = elementTreeRootAndNamespace('houses.xml')

# Insert the namespace before each tag when when finding current number of dogs,
# as ElementTree requires the namespace to be prefixed within {...} when a
# namespace is used in the document.
dogs = elementTree.find('{ns}house/{ns}dogs'.format(ns = namespace))

# Increase the number of dogs by one
dogs.text = str(int(dogs.text) + 1)

# Write the result to the new file houses2.xml.
elementTree.write('houses2.xml')