Python webapp2 模块，cached_property() 实例源码

def test_cached_property(self):
        count = [0]

        class Foo(object):
            @webapp2.cached_property
            def bar(self):
                count[0] += 1
                return count[0]

        self.assertTrue(isinstance(Foo.bar, webapp2.cached_property))

        foo = Foo()
        self.assertEqual(foo.bar, 1)
        self.assertEqual(foo.bar, 1)
        self.assertEqual(foo.bar, 1)