python override\uuuu new\uuuuu无法将参数发送到\uuuu init__

我有一个非常简单的程序，它将一个singleton实现为一个基类，这个基类简单地定义了一个新的，用于实现“singleness”。但是，我不能再将参数发送到init方法-当我发送参数时，我从singletonnew超级调用中得到一个“TypeError:object（）不带参数”：

class Singleton(object):
    _instances = {}

    def __new__(cls, *args, **kwargs):
        print(args, kwargs)
        if cls._instances.get(cls, None) is None:
            cls._instances[cls] = super(Singleton, cls).__new__(cls, *args, **kwargs)
        return Singleton._instances[cls]


class OneOfAKind(Singleton):

    def __init__(self):
        print('--> OneOfAKind __init__')
        Singleton.__init__(self)


class OneOfAKind2(Singleton):

    def __init__(self, onearg):
        print('--> OneOfAKind2 __init__')
        Singleton.__init__(self)
        self._onearg = onearg


x = OneOfAKind()
y = OneOfAKind()
print(x == y)
X = OneOfAKind2('testing')

输出为：

() {}
Traceback (most recent call last):
  File "./mytest.py", line 29, in <module>
    x = OneOfAKind()
  File "./mytest.py", line 10, in __new__
    cls._instances[cls] = super(Singleton, cls).__new__(cls, (), {})
TypeError: object() takes no parameters

（）{}
回溯（最近一次呼叫最后一次）：
文件“/mytest.py”，第29行，在
x=同类中的一种（）
文件“/mytest.py”，第10行，新的__
cls._instances[cls]=super（Singleton，cls）。uu new_uu（cls，（），{}）
TypeError:对象（）不接受任何参数

对，因为您从

super

继承并调用的

对象不接受任何参数：

In [54]: object('foo', 'bar')
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-54-f03d0963548d> in <module>()
----> 1 object('foo', 'bar')

TypeError: object() takes no parameters

然后：

我想你正在使用Python 3？太棒了！谢谢
import six ## used for compatibility between py2 and py3

class Singleton(type):
    _instances = {}

    def __call__(cls, *args, **kwargs):
        if Singleton._instances.get(cls, None) is None:
            Singleton._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
        return Singleton._instances[cls]

@six.add_metaclass(Singleton)
class OneOfAKind(object):

    def __init__(self):
        print('--> OneOfAKind __init__')

@six.add_metaclass(Singleton)
class OneOfAKind2(object):

    def __init__(self, onearg):
        print('--> OneOfAKind2 __init__')
        self._onearg = onearg

In [64]: OneOfAKind() == OneOfAKind()
--> OneOfAKind __init__
Out[64]: True

In [65]: OneOfAKind() == OneOfAKind()
Out[65]: True

In [66]: OneOfAKind() == OneOfAKind2('foo')
Out[66]: False