当我撰写并形式化问题时,我找到了答案(经常发生在我身上)。也许这可以帮助别人。
我的解决方案如下:
def __getattr__ ( self, attr : str ) -> str:
return self.__getitem__(attr)
def __setattr__ ( self, attr : str, val : str ) -> None:
if attr == 'store':
super().__setattr__(attr,val)
else:
self.__setitem__(attr,val)
关键是store
属性必须从基类中分离出来并调用以避免递归。很简单,但我很容易错过!
UPDATE:
我添加了添加您不想保留的属性的功能store
(即属性的通常含义)。我也实施了store
as an OrderedDict
,但这仅适用于我的用例。显然set_inst_attr
例外是临时的/占位符。
from collections import MutableMapping, OrderedDict
class ODictish (MutableMapping):
"""
An OrderedDict-like mapping object.
Provides __getattr__ and __setattr__ as aliases for __getitem__
and __setitem__.
Attributes which you do not want to keep in 'store' can be set with
self.set_inst_attr.
"""
def __init__ ( self , od=None):
if od is None: od = OrderedDict()
super().__setattr__('store', OrderedDict(od))
def __getitem__ ( self, key ):
return self.store[key]
def __setitem__ ( self, key, val ):
self.store[key] = val
def __delitem__ ( self, key ):
del self.store[key]
def __iter__ ( self ):
return iter(self.store)
def __len__ ( self ):
return len(self.store)
def __repr__ ( self ):
return repr(self.store)
def __getattr__ ( self, attr ):
if attr in vars(self):
return vars(self)[attr]
return self.__getitem__(attr)
def __setattr__ ( self, attr, val ):
if attr in vars(self):
self.set_inst_attr(attr,val)
else:
self.__setitem__(attr,val)
def set_inst_attr ( self, attr, val ):
if attr == 'store':
raise Exception("Don't do that.")
super().__setattr__(attr,val)
def move_to_end ( self, key, last=True ):
self.store.move_to_end(key,last)