元类传递类名作为参数

Question

我有类似的元类：

class Metaclass(type):
    def __new__(self, name, bases, attrs):

        for k, v in attrs.iteritems():
            if isinstance(v, types.FunctionType):
               attrs[k] = self.decorator(v)
        return super(MetaClass, self).__new__(self, name, bases, attrs)

    @classmethod
    def decorator(cls, func):
        def wrapper(*args, **kwargs):
            print(func.__name__)

但我无法得到 func.__class__.__name__ 它打印元类。我想得到func.__name__ 的班级名称。 显然这是不可能的python 2.7（？） 我可以将类名作为参数传递吗？对于调用此装饰器的方法？ 即如果testmethod 调用元类装饰器并将Testclass 作为参数传递。因此，如果我知道func.__name__ 来自特定班级，请做特定的事情。

Answer 1

您忘记从装饰器返回包装器。应该是：

class Metaclass(type):
    def __new__(self, name, bases, attrs):

        for k, v in attrs.iteritems():
            if isinstance(v, types.FunctionType):
               attrs[k] = self.decorator(v)
        return super(Metaclass, self).__new__(self, name, bases, attrs)

    @classmethod
    def decorator(cls, func):
        def wrapper(*args, **kwargs):
            print(func.__name__)
        return wrapper

您现在可以使用元类：

>>> class TestClass(object):
    __metaclass__ = Metaclass
    def foo(self):
        return "bar"

>>> t = TestClass()
>>> x = t.foo()
foo
>>> print x
None

方法已被包装器正确替换。

---

在您之前（现已删除）的问题中，您要求 打印“此方法来自 Testclass”。您可以简单地将类名传递给装饰器：

class Metaclass(type):
    def __new__(self, name, bases, attrs):

        for k, v in attrs.iteritems():
            if isinstance(v, types.FunctionType):
               attrs[k] = self.decorator(v, name)
        return super(Metaclass, self).__new__(self, name, bases, attrs)

    @classmethod
    def decorator(cls, func, name):
        def wrapper(self, *args, **kwargs):
            print "%s defined in %s called from %s instance" % (func.__name__,
                name, self.__class__.__name__)
            return func(self, *args, **kwargs)
        return wrapper

你现在获得：

>>> class TestClass(object):
    __metaclass__ = Metaclass
    def foo(self):
        return "bar"


>>> t = TestClass()
>>> x = t.foo()
foo defined in TestClass called from TestClass instance
>>> print x
bar