member_decorator2.py

from functools import wraps


def my_decorator(x=None):
    def outer(func):
        @wraps(func)
        def inner(self):
            y = 10
            print "x + {0} = {1}".format(y, x + y)
            func(self)
        return inner
    return outer


class SomeClass(object):
    @my_decorator(x=5)
    def foo(self):
        print 'Foo'


if __name__ == '__main__':
    instance = SomeClass()
    assert id(instance.foo) == id(instance.foo)
    instance.foo()