初始化时引发TypeError的子类化属性__

Question

我已经对属性进行了子类化，试图向它添加一个锁，以便对它的访问是原子的（一次只能有一个线程对它进行读写）。但我在初始化时遇到了错误，也不知道为什么。你知道吗

要清楚的是：我不想做描述符，我希望能够使用@atomic\u property decorator而不是@property

class atomic_property(property):

    def __init__(self, func, name=None, doc=None):
        self.__name__ = name or func.__name__
        self.__module__ = func.__module__
        self.__doc__ = doc or func.__doc__
        self.func = func
        self.lock = threading.Lock()

    def __get__(self, obj, objtype=None):
        with self.lock:
            return self.func(obj)

    def __set__(self, obj, value):
        with self.lock:
            return self.func(obj, value)

这是伊普顿的回溯。你知道吗

    In [12]: class a(object):
    def __init__(self):
        self._b = 1
    @utils.atomic_property
    def b(self):
        return self._b
    @b.setter
    def b(self, val):
        self._b = val
   ....:         
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-12-daec89385bc3> in <module>()
----> 1 class a(object):
      2     def __init__(self):
      3         self._b = 1
      4     @utils.atomic_property
      5     def b(self):

<ipython-input-12-daec89385bc3> in a()
      5     def b(self):
      6         return self._b
----> 7     @b.setter
      8     def b(self, val):
      9         self._b = val

TypeError: __init__() takes from 2 to 4 positional arguments but 5 were given

Answer 1

似乎使用property.setter再次调用__init__，这看起来很奇怪（再次初始化同一个对象？）你知道吗

不管怎样，你需要让property做它的工作，如果你根本不使用property.__init__，你怎么能期望它正常工作呢？你可以这样做，例如：

class atomic_property(property):

    def __init__(self, *args, **kwargs):
        #print(args,kwargs) #uncomment to see this be called again when using .setter !
        super(atomic_property,self).__init__(*args,**kwargs)       
        self.lock = threading.Lock()

    def __get__(self, obj, objtype=None):
        with self.lock:
            return super(atomic_property,self).__get__(obj,objtype)

    def __set__(self, obj, value):
        with self.lock:
            return super(atomic_property,self).__set__(obj,value)