我正在尝试用xmltodict生成XML。为此,我需要基于OrderedDict生成结构。我在第一次执行“.xml()”方法时得到了预期的行为,但在第二次执行时,我又得到了第二次添加的子元素。你知道吗
from collections import OrderedDict
import xmltodict
class XMLObject(object):
__ns__ = ''
def __init__(self, parent=None, **kwargs):
self.parent = None
if parent:
self.__ns__ = parent.__ns__
self.parent = parent
self._attrib = OrderedDict()
self.children = []
def __setitem__(self, key, value):
self._attrib[key] = value
def __getitem__(self, item):
return self._attrib[item]
@property
def tagname(self):
return (self.__ns__ + ':' + self.__tag__) if self.__ns__ else self.__tag__
def object(self):
store = OrderedDict()
print id(store)
tag = self.tagname
print tag
store[tag] = self._attrib
print self.children
for child in self.children:
print "-" + child.tagname
if not child.tagname in store[tag]:
store[tag][child.tagname] = list()
store[tag][child.tagname].append(child.object()[child.tagname])
return store
def xml(self, pretty=False, clean=False):
xml = xmltodict.unparse(self.object())
return xml
class A(XMLObject):
__tag__ = 'A'
def __init__(self, *args, **kwargs):
super(A, self).__init__(*args, **kwargs)
self.children = [B(parent=self)]
class B(XMLObject):
__tag__ = 'B'
if __name__ == '__main__':
obj = A()
print obj.xml()
print obj.xml()
print obj.xml()
在ipython控制台中,这是结果。你知道吗
In [1]: from question import *
In [2]: obj = A()
In [3]: obj.xml()
35393280
A
[<question.B object at 0x7f3bc226f890>]
-B
35394720
B
[]
Out[3]: u'<?xml version="1.0" encoding="utf-8"?>\n<A><B></B></A>'
In [4]: obj.xml()
35487136
A
[<question.B object at 0x7f3bc226f890>]
-B
35487936
B
[]
Out[4]: u'<?xml version="1.0" encoding="utf-8"?>\n<A><B></B><B></B></A>'
In [5]: obj.xml()
35487136
A
[<question.B object at 0x7f3bc226f890>]
-B
35488896
B
[]
Out[5]: u'<?xml version="1.0" encoding="utf-8"?>\n<A><B></B><B></B><B></B></A>'
您正在
OrderedDict()
中存储对self._attrib
的引用:这不是副本;您在这里与
store
对象共享instance属性。你知道吗因此,当您稍后添加到字典时,您正在更改
self._attrib
所指的同一对象:不重置此状态;self.\u attrib
remains altered when
A.xml()`returns。你知道吗您很可能希望使用
self._attrib
对象的副本:这会产生一个浅副本;} 。创建递归深度副本。你知道吗
self._attrib
中对可变对象的任何引用都会被复制。使用^{相关问题 更多 >
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