def scalar_set_undo (self, instance, private_attributename):
        """Undo the changes done by the assignment of an instance"""
        newvalue = getattr(instance, private_attributename)
        delattr(instance, private_attributename)
        return self.scalar_set_redo,(instance, private_attributename, newvalue)
Undo the changes done by the assignment of an instance
recipes/Python/306866_A_basic_undo_mechanism/recipe-306866.py