Question

我试图在python＆＃39; ElementTree中为Element和xml.etree.ElementTree创建一个小插件，这样可以使用以下符号：

root = ET.fromstring('<root><a><b attr1="2"/></a></root>')
element1 = root.a
element2 = root.a.b
attr = root.a.b.attr

我试过这个：

import xml.etree.ElementTree as _ET

def __getattr__(self, key):
    return self.find('./' + key)

class ElementTree(_ET.ElementTree):
    __getattr__ = __getattr__


class Element(_ET.Element):
    __getattr__ = __getattr__

但这不起作用，因为ET.parse，ET.fromstring，ET.ElementTree.find等将始终返回内部Element和ElementTree个对象。

Monkeypatching类也不起作用：

>>> xml.etree.ElementTree.Element.__getattr__ = lambda x: x
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-4-bacb0a64c2e5> in <module>()
----> 1 xml.etree.ElementTree.Element.__getattr__ = lambda x: x

TypeError: can't set attributes of built-in/extension type 'xml.etree.ElementTree.Element'

这是否可行而不复制python etree模块然后添加__getattr__？

相关：How to inherit ElementTree.Element class in python?

Answer 1

由于import of the Element and XMLParser's C implementation：

，无法覆盖课程

# Import the C accelerators
try:
    # Element is going to be shadowed by the C implementation. We need to keep
    # the Python version of it accessible for some "creative" by external code
    # (see tests)
    _Element_Py = Element

    # Element, SubElement, ParseError, TreeBuilder, XMLParser
    from _elementtree import *
except ImportError:
    pass

模块_elementtree位于Modules/_elementtree.c。

解决方案是复制python etree模块，并将导入更改为：

_Element_Py = Element

我做了一个简单的实现：https://github.com/arve0/objectifiedetree

像这样使用：

from objectifiedetree import *

tree = ET.parse('/path/to/file.xml')
# dot notation :-)
el = tree.xpath.to.your.element

# use normal etree attributes
print(el.attrib)

# access name crashes
attrib_el = el.find('./attrib')

Answer 2

我遇到了类似的问题，无意中找到了一种快速的解决方法：
我在Python 3.7之前的版本中导入了xmlschema，并且用ET.Element猴子setattr的补丁都没有问题。

继承或模拟pythons etree.ElementTree.Element可能吗？

2 个答案: