| from test import test_support, seq_tests | |
| import gc | |
| class TupleTest(seq_tests.CommonTest): | |
| type2test = tuple | |
| def test_constructors(self): | |
| super(TupleTest, self).test_constructors() | |
| # 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.assertTrue(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(TupleTest, self).test_truth() | |
| self.assertTrue(not ()) | |
| self.assertTrue((42, )) | |
| def test_len(self): | |
| super(TupleTest, self).test_len() | |
| self.assertEqual(len(()), 0) | |
| self.assertEqual(len((0,)), 1) | |
| self.assertEqual(len((0, 1, 2)), 3) | |
| def test_iadd(self): | |
| super(TupleTest, self).test_iadd() | |
| u = (0, 1) | |
| u2 = u | |
| u += (2, 3) | |
| self.assertTrue(u is not u2) | |
| def test_imul(self): | |
| super(TupleTest, self).test_imul() | |
| u = (0, 1) | |
| u2 = u | |
| u *= 3 | |
| self.assertTrue(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())), 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 = 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 + zip(base) | |
| collisions = len(inps) - len(set(map(hash, inps))) | |
| self.assertTrue(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) | |
| @test_support.cpython_only | |
| 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])) | |
| @test_support.cpython_only | |
| def test_track_dynamic(self): | |
| # Test GC-optimization of dynamically constructed tuples. | |
| self.check_track_dynamic(tuple, False) | |
| @test_support.cpython_only | |
| def test_track_subtypes(self): | |
| # Tuple subtypes must always be tracked | |
| class MyTuple(tuple): | |
| pass | |
| self.check_track_dynamic(MyTuple, True) | |
| @test_support.cpython_only | |
| def test_bug7466(self): | |
| # Trying to untrack an unfinished tuple could crash Python | |
| self._not_tracked(tuple(gc.collect() for i in range(101))) | |
| def test_main(): | |
| test_support.run_unittest(TupleTest) | |
| if __name__=="__main__": | |
| test_main() |