在Python中使用ElementTree发出名称空间规范

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我试图发出带有元素树的XML文件，其中包含XML声明和名称空间。这是我的示例代码：

I am trying to emit an XML file with element-tree that contains an XML declaration and namespaces. Here is my sample code:

from xml.etree import ElementTree as ET ET.register_namespace('com',"wwwpany") #some name # build a tree structure root = ET.Element("STUFF") body = ET.SubElement(root, "MORE_STUFF") body.text = "STUFF EVERYWHERE!" # wrap it in an ElementTree instance, and save as XML tree = ET.ElementTree(root) tree.write("page.xml", xml_declaration=True, method="xml" )

但是，两者都不<？xml 标记也不会出现，也不会显示任何名称空间/前缀信息。

However, neither the <?xml tag comes out nor any namespace/prefix information. I'm more than a little confused here.

推荐答案

尽管文档否则，我只能得到<？xml> 声明通过同时指定xml_declaration和编码。

Although the docs say otherwise, I only was able to get an <?xml> declaration by specifying both the xml_declaration and the encoding.

您必须在已注册的名称空间中声明节点，才能在文件中的节点上获得名称空间。这是代码的固定版本：

You have to declare nodes in the namespace you've registered to get the namespace on the nodes in the file. Here's a fixed version of your code:

from xml.etree import ElementTree as ET ET.register_namespace('com',"wwwpany") #some name # build a tree structure root = ET.Element("{wwwpany}STUFF") body = ET.SubElement(root, "{wwwpany}MORE_STUFF") body.text = "STUFF EVERYWHERE!" # wrap it in an ElementTree instance, and save as XML tree = ET.ElementTree(root) tree.write("page.xml", xml_declaration=True,encoding='utf-8', method="xml")

输出（page.xml）

Output (page.xml)

<?xml version='1.0' encoding='utf-8'?><com:STUFF xmlns:com="wwwpany"><com:MORE_STUFF>STUFF EVERYWHERE!</com:MORE_STUFF></com:STUFF>

ElementTree也不漂亮。这是输出精美的输出：

ElementTree doesn't pretty-print either. Here's pretty-printed output:

<?xml version='1.0' encoding='utf-8'?> <com:STUFF xmlns:com="wwwpany"> <com:MORE_STUFF>STUFF EVERYWHERE!</com:MORE_STUFF> </com:STUFF>

您也可以声明默认名称空间，并且不要t需要注册一个：

You can also declare a default namespace and don't need to register one:

from xml.etree import ElementTree as ET # build a tree structure root = ET.Element("{wwwpany}STUFF") body = ET.SubElement(root, "{wwwpany}MORE_STUFF") body.text = "STUFF EVERYWHERE!" # wrap it in an ElementTree instance, and save as XML tree = ET.ElementTree(root) tree.write("page.xml", xml_declaration=True,encoding='utf-8', method="xml",default_namespace='wwwpany')

输出（漂亮的打印间距是我的）

Output (pretty-print spacing is mine)

<?xml version='1.0' encoding='utf-8'?> <STUFF xmlns="wwwpany"> <MORE_STUFF>STUFF EVERYWHERE!</MORE_STUFF> </STUFF>