test_traitlets_enum.py 文件源码

def test_ctor_with_default_value_none_and_allow_none(self):
        class Example2(HasTraits):
            color1 = UseEnum(Color, default_value=None, allow_none=True)
            color2 = UseEnum(Color, allow_none=True)

        example = Example2()
        self.assertIs(example.color1, None)
        self.assertIs(example.color2, None)