python - 将标准库中的属性添加到 Python 字典

Question

我想知道是否可以向 Python 字典添加属性？

class myclass():
    def __init__(): 
     self.mydict = {}  # initialize a regular dict
     self.mydict.newattribute = "A description of what this dictionary will hold"
     >>> AttributeError: 'dict' object has no attribute 'newattribute'
     setattr(self.mydict, "attribute", "A description of what this dictionary will hold"
     >>> AttributeError: 'dict' object has no attribute 'newattribute'

有没有办法快速添加我的描述属性，而不必复制 dict 类和重载构造函数。我以为这很简单，但我想我错了。

Answer 1

只需从 dict 派生:

class MyDict(dict):
    pass

MyDict 的实例表现得像一个dict，但可以有自定义属性:

>>> d = MyDict()
>>> d.my_attr = "whatever"
>>> d.my_attr
'whatever'