Python-сообщество

class Decorator:
    def __init__(self, method):
        self.method = method

    def __call__(self, *args):
        print 'decorator-class arguments: ', args
        return self.method(*args)


def decorator(method):
    def inner(*args):
        print 'decorator-function arguments: ', args
        return method(*args)
    return inner

class My:
    def test(self, i):
        return i+1

obj = My()
print obj.test(100)

decorator-function arguments:  (<__main__.My instance at 0x01D1D878>, 100)
101

decorator-class arguments:  (100,)
Traceback (most recent call last):
  File "C:\Users\dima\Documents\NetBeansProjects\db\src\decorators.py", line 42, in <module>
    print m.test(100)
  File "C:\Users\dima\Documents\NetBeansProjects\db\src\decorators.py", line 9, in __call__
    return self.method(*args)
TypeError: test() takes exactly 2 arguments (1 given)

class Decorator:
    def __init__(self, param=None):
        pass

    def __call__(self, method):
        def inner(*args):
            print 'decorator-class arguments: ', args
            return method(*args)
        return inner

decorator-class arguments:  (<__main__.My instance at 0x01E1D940>, 100)
101

class My:
    @Decorator()
    def test(self, i):
        return i+1

class Parametrized(object):
    """
        A baseclass that allows to defer instance creation until
        it gets a non-keyword argument (specifying the rule).

        For example here's what it does to `compute`. A trivial case:

            >>> compute(lambda:None)
            compute(None)

        `compute` can also take additional arguments:

            >>> compute(lambda:None, resetting_to=0)
            compute(None)

        But we want to be able to use it as a decorator and still pass
        additional arguments, so the following should work:

            >>> compute(resetting_to=0)(lambda:None)
            compute(None)

        It worked because the first call was intercepted in
        Parametrized.__new__ and returned the lambda that acts as a
        real decorator:

            >>> compute(resetting_to=0)
            <function <lambda> at 0x00C343B0>

    """
    def __new__(cls, *args, **kw):
        if not args:
            return lambda _: cls(_, **kw)
        return object.__new__(cls)