The reduced usecase (story?) is the following The customer requests the following @? class somename (?): an_attr_a = ADescriptor(somestuff)

The reduced usecase (story?) is the following The customer requests the following @? class somename (?): an_attr_a = ADescriptor(somestuff) an_attr_1 = ADescriptor(somestuff) an_attr_a1 = ADescriptor(somestuff) One of their expectations is that the attributes have their definition order stored somewhere. You may either use the decorator method, or the metaclass method