| from test import support, seq_tests |
| |
| import gc |
| |
| class TupleTest(seq_tests.CommonTest): |
| type2test = tuple |
| |
| def test_constructors(self): |
| super().test_len() |
| # calling built-in types without argument must return empty |
| self.assertEqual(tuple(), ()) |
| t0_3 = (0, 1, 2, 3) |
| t0_3_bis = tuple(t0_3) |
| self.assert_(t0_3 is t0_3_bis) |
| self.assertEqual(tuple([]), ()) |
| self.assertEqual(tuple([0, 1, 2, 3]), (0, 1, 2, 3)) |
| self.assertEqual(tuple(''), ()) |
| self.assertEqual(tuple('spam'), ('s', 'p', 'a', 'm')) |
| |
| def test_truth(self): |
| super().test_truth() |
| self.assert_(not ()) |
| self.assert_((42, )) |
| |
| def test_len(self): |
| super().test_len() |
| self.assertEqual(len(()), 0) |
| self.assertEqual(len((0,)), 1) |
| self.assertEqual(len((0, 1, 2)), 3) |
| |
| def test_iadd(self): |
| super().test_iadd() |
| u = (0, 1) |
| u2 = u |
| u += (2, 3) |
| self.assert_(u is not u2) |
| |
| def test_imul(self): |
| super().test_imul() |
| u = (0, 1) |
| u2 = u |
| u *= 3 |
| self.assert_(u is not u2) |
| |
| def test_tupleresizebug(self): |
| # Check that a specific bug in _PyTuple_Resize() is squashed. |
| def f(): |
| for i in range(1000): |
| yield i |
| self.assertEqual(list(tuple(f())), list(range(1000))) |
| |
| def test_hash(self): |
| # See SF bug 942952: Weakness in tuple hash |
| # The hash should: |
| # be non-commutative |
| # should spread-out closely spaced values |
| # should not exhibit cancellation in tuples like (x,(x,y)) |
| # should be distinct from element hashes: hash(x)!=hash((x,)) |
| # This test exercises those cases. |
| # For a pure random hash and N=50, the expected number of occupied |
| # buckets when tossing 252,600 balls into 2**32 buckets |
| # is 252,592.6, or about 7.4 expected collisions. The |
| # standard deviation is 2.73. On a box with 64-bit hash |
| # codes, no collisions are expected. Here we accept no |
| # more than 15 collisions. Any worse and the hash function |
| # is sorely suspect. |
| |
| N=50 |
| base = list(range(N)) |
| xp = [(i, j) for i in base for j in base] |
| inps = base + [(i, j) for i in base for j in xp] + \ |
| [(i, j) for i in xp for j in base] + xp + list(zip(base)) |
| collisions = len(inps) - len(set(map(hash, inps))) |
| self.assert_(collisions <= 15) |
| |
| def test_repr(self): |
| l0 = tuple() |
| l2 = (0, 1, 2) |
| a0 = self.type2test(l0) |
| a2 = self.type2test(l2) |
| |
| self.assertEqual(str(a0), repr(l0)) |
| self.assertEqual(str(a2), repr(l2)) |
| self.assertEqual(repr(a0), "()") |
| self.assertEqual(repr(a2), "(0, 1, 2)") |
| |
| def _not_tracked(self, t): |
| # Nested tuples can take several collections to untrack |
| gc.collect() |
| gc.collect() |
| self.assertFalse(gc.is_tracked(t), t) |
| |
| def _tracked(self, t): |
| self.assertTrue(gc.is_tracked(t), t) |
| gc.collect() |
| gc.collect() |
| self.assertTrue(gc.is_tracked(t), t) |
| |
| def test_track_literals(self): |
| # Test GC-optimization of tuple literals |
| x, y, z = 1.5, "a", [] |
| |
| self._not_tracked(()) |
| self._not_tracked((1,)) |
| self._not_tracked((1, 2)) |
| self._not_tracked((1, 2, "a")) |
| self._not_tracked((1, 2, (None, True, False, ()), int)) |
| self._not_tracked((object(),)) |
| self._not_tracked(((1, x), y, (2, 3))) |
| |
| # Tuples with mutable elements are always tracked, even if those |
| # elements are not tracked right now. |
| self._tracked(([],)) |
| self._tracked(([1],)) |
| self._tracked(({},)) |
| self._tracked((set(),)) |
| self._tracked((x, y, z)) |
| |
| def check_track_dynamic(self, tp, always_track): |
| x, y, z = 1.5, "a", [] |
| |
| check = self._tracked if always_track else self._not_tracked |
| check(tp()) |
| check(tp([])) |
| check(tp(set())) |
| check(tp([1, x, y])) |
| check(tp(obj for obj in [1, x, y])) |
| check(tp(set([1, x, y]))) |
| check(tp(tuple([obj]) for obj in [1, x, y])) |
| check(tuple(tp([obj]) for obj in [1, x, y])) |
| |
| self._tracked(tp([z])) |
| self._tracked(tp([[x, y]])) |
| self._tracked(tp([{x: y}])) |
| self._tracked(tp(obj for obj in [x, y, z])) |
| self._tracked(tp(tuple([obj]) for obj in [x, y, z])) |
| self._tracked(tuple(tp([obj]) for obj in [x, y, z])) |
| |
| def test_track_dynamic(self): |
| # Test GC-optimization of dynamically constructed tuples. |
| self.check_track_dynamic(tuple, False) |
| |
| def test_track_subtypes(self): |
| # Tuple subtypes must always be tracked |
| class MyTuple(tuple): |
| pass |
| self.check_track_dynamic(MyTuple, True) |
| |
| |
| def test_main(): |
| support.run_unittest(TupleTest) |
| |
| if __name__=="__main__": |
| test_main() |