def uninstrument_attribute(self, key, propagated=False):
        if key not in self:
            return
        if propagated:
            if key in self.local_attrs:
                return  # don't get rid of local attr
        else:
            del self.local_attrs[key]
            self.uninstall_descriptor(key)
        del self[key]
        for cls in self.class_.__subclasses__():
            manager = manager_of_class(cls)
            if manager:
                manager.uninstrument_attribute(key, True)
dataset/ETHPy150Open RoseOu/flasky/venv/lib/python2.7/site-packages/sqlalchemy/orm/instrumentation.py/ClassManager.uninstrument_attribute/original