我正试图将属性动态地附加到一个类（
Registry
）上，以便于访问一个字典中的值。我使用
defaultdict
来定义字典，默认值是一个空的
list
。
但由于我在定义属性时访问字典中的列表值的方式，我最终发现所有属性都指向同一个列表对象。
Gist: https://gist.github.com/subhashb/adb75a3a05a611c3d9193da695d46dd4
from collections import defaultdict from enum import Enum class ElementTypes(Enum): PHONE = "PHONE" CAR = "CAR" class Registry: def __new__(cls, *args, **kwargs): cls.setup_properties() instance = super(Registry, cls).__new__(cls, *args, **kwargs) return instance def __init__(self): self._elements = {} def register(self, element_type, item): if element_type.value not in self._elements: self._elements[element_type.value] = [] self._elements[element_type.value].append(item) def get(self, element_type): return self._elements[element_type.value] @classmethod def setup_properties(cls): for item in ElementTypes: prop_name = item.value prop = property(lambda self: getattr(self, "get")(item)) setattr(Registry, prop_name.lower(), prop) registry = Registry() registry.register(ElementTypes.PHONE, "phone1") registry.register(ElementTypes.PHONE, "phone2") registry.register(ElementTypes.CAR, "car1") registry.register(ElementTypes.CAR, "car2") assert dict(registry._elements) == { "CAR": ["car1", "car2"], "PHONE": ["phone1", "phone2"], assert hasattr(registry, "phone") assert hasattr(registry, "car") assert registry.car == ["car1", "car2"] assert registry.phone == ["phone1", "phone2"] # This fails我如何将属性中的代码定义为真正的动态，并在dict中获得对单个列表值的访问？
