| from test import test_support, seq_tests |
| |
| class TupleTest(seq_tests.CommonTest): |
| type2test = tuple |
| |
| def test_constructors(self): |
| super(TupleTest, self).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(TupleTest, self).test_truth() |
| self.assert_(not ()) |
| self.assert_((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.assert_(u is not u2) |
| |
| def test_imul(self): |
| super(TupleTest, self).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())), 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.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 test_main(): |
| test_support.run_unittest(TupleTest) |
| |
| if __name__=="__main__": |
| test_main() |
