最好的方法是定义__slots__。这样你的实例就不能有新的属性。

ks = ['ab', 'cd']
vs = [12, 34]

class C(dict):
    __slots__ = []
    def __init__(self, ks, vs): self.update(zip(ks, vs))
    def __getattr__(self, key): return self[key]

if __name__ == "__main__":
    c = C(ks, vs)
    print c.ab

打印12

    c.ab = 33

'C'对象没有属性'ab'

class atdict(dict):
  def __init__(self, value, **kwargs):
    super().__init__(**kwargs)
    self.__dict = value

  def __getattr__(self, name):
    for key in self.__dict:
      if type(self.__dict[key]) is list:
        for idx, item in enumerate(self.__dict[key]):
          if type(item) is dict:
            self.__dict[key][idx] = atdict(item)
      if type(self.__dict[key]) is dict:
        self.__dict[key] = atdict(self.__dict[key])
    return self.__dict[name]



d1 = atdict({'a' : {'b': [{'c': 1}, 2]}})

print(d1.a.b[0].c)

输出为:

>> 1

如果需求是基于某些实例属性动态生成属性，那么下面的代码可能会有用:

import random  

class Foo:
    def __init__(self, prop_names: List[str], should_property_be_zero: bool = False) -> None:
        self.prop_names = prop_names
        self.should_property_be_zero = should_property_be_zero
        
    def create_properties(self):
        for name in self.prop_names:
            setattr(self.__class__, name, property(fget=lambda self: 0 if self.should_property_be_zero else random.randint(1, 100)))

需要注意的重要一点是使用setattr(self。__class__进行名称,…),而不是setattr(自我、名称…)

使用的例子:

In [261]: prop_names = ['a', 'b']

In [262]: ff = Foo(prop_names=prop_names, should_property_be_zero=False)

In [263]: ff.create_properties()

In [264]: ff.a
Out[264]: 10

In [265]: ff.b
Out[265]: 37

In [266]: ft = Foo(prop_names=prop_names, should_property_be_zero=True)

In [267]: ft.create_properties()

In [268]: ft.a
Out[268]: 0

In [269]: ft.b
Out[269]: 0

设置属性将引发AttributeError:不能按预期设置属性:

In [270]: ff.a = 5
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-270-5f9cad5b617d> in <module>
----> 1 ff.a = 5

AttributeError: can't set attribute

In [271]: ft.a = 5
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-271-65e7b8e25b67> in <module>
----> 1 ft.a = 5

AttributeError: can't set attribute

对我有用的是:

class C:
    def __init__(self):
        self._x=None

    def g(self):
        return self._x

    def s(self, x):
        self._x = x

    def d(self):
        del self._x

    def s2(self,x):
        self._x=x+x

    x=property(g,s,d)


c = C()
c.x="a"
print(c.x)

C.x=property(C.g, C.s2)
C.x=C.x.deleter(C.d)
c2 = C()
c2.x="a"
print(c2.x)

输出

a
aa

你可以使用下面的代码来使用字典对象更新类属性:

class ExampleClass():
    def __init__(self, argv):
        for key, val in argv.items():
            self.__dict__[key] = val

if __name__ == '__main__':
    argv = {'intro': 'Hello World!'}
    instance = ExampleClass(argv)
    print instance.intro

动态附加属性的唯一方法是用新属性创建一个新类及其实例。

class Holder: p = property(lambda x: vs[i], self.fn_readonly)
setattr(self, k, Holder().p)