Method rev

Lib/test/test_descr.py:2880–2886

(self)

        class madtuple(tuple):
            _rev = None
            def rev(self):
                if self._rev is not None:
                    return self._rev
                L = list(self)
                L.reverse()
                self._rev = self.__class__(L)
                return self._rev
        a = madtuple((1,2,3,4,5,6,7,8,9,0))
        self.assertEqual(a, (1,2,3,4,5,6,7,8,9,0))
        self.assertEqual(a.rev(), madtuple((0,9,8,7,6,5,4,3,2,1)))