def test_delete_first(self): expected = PositionalList.from_iterable('bc') pl = PositionalList() a = pl.add_first('a') b = pl.add_after(a, 'b') c = pl.add_last('c') db = pl.delete(a) self.assertEqual(pl, expected) self.assertEqual(db, 'a')
def test_delete_len(self): pl = PositionalList() a = pl.add_first('a') b = pl.add_after(a, 'b') c = pl.add_last('c') d = pl.add_after(c, 'd') self.assertEqual(len(pl), 4) pl.delete(a) self.assertEqual(len(pl), 3) pl.delete(pl.first()) self.assertEqual(len(pl), 2) pl.delete(pl.last()) self.assertEqual(len(pl), 1) self.assertTrue(pl) pl.delete(c) self.assertEqual(len(pl), 0) self.assertFalse(pl)