为什么 hasattr 返回错误的结果？

Question

下面是我的测试代码：

import functools

class LazyLoader(object):

    def __init__(self, klass, *args, **kwargs):

        self.klass = klass

        self.args = args

        self.kwargs = kwargs

        self.instance = None

    def __getattr__(self, name):

        return functools.partial(self.__run_method, name)

    def __run_method(self, __name, *args, **kwargs):

        if self.instance is None:

            self.instance = self.klass(*self.args, **self.kwargs)

        return getattr(self.instance, __name)(*args, **kwargs)

class SchedulerReportClient(object):

    def method(self):

        print 'method called'

    def __getattr__(self, name):

        print '__getattr__ called'

        return functools.partial(self.__run_method, name)

    def __run_method(self, __name, *args, **kwargs):

        print '__run_method called'

        return getattr(self, __name)(*args, **kwargs)

if __name__ == "__main__":

    a = SchedulerReportClient()

    entity = LazyLoader(a)

    print hasattr(entity, 'obj_to_primitive')

    print(callable(entity.obj_to_primitive))

    print entity.__class__.__name__

    if hasattr(entity, 'obj_to_primitive') and callable(entity.obj_to_primitive):

        entity.obj_to_primitive()

出局是：

True

True

Traceback (most recent call last):

LazyLoader

  File "C:/Users/chen/PycharmProjects/pytest/main", line 42, in <module>

    entity.obj_to_primitive()

  File "C:/Users/chen/PycharmProjects/pytest/main", line 17, in __run_method

    self.instance = self.klass(*self.args, **self.kwargs)

TypeError: 'SchedulerReportClient' object is not callable

代码大部分在openstack nova中，我复制了一些。

obj_to_primitiveclass 中没有方法SchedulerReportClient，为什么 hasattr 和 callable 函数返回 true？

CentOS7.4 与 Python2.7。