/Lib/test/test_hash.py
http://unladen-swallow.googlecode.com/ · Python · 143 lines · 103 code · 28 blank · 12 comment · 9 complexity · c1a55326372fe00934fa6d665812c549 MD5 · raw file
- # test the invariant that
- # iff a==b then hash(a)==hash(b)
- #
- # Also test that hash implementations are inherited as expected
- import unittest
- from test import test_support
- from collections import Hashable
- class HashEqualityTestCase(unittest.TestCase):
- def same_hash(self, *objlist):
- # Hash each object given and fail if
- # the hash values are not all the same.
- hashed = map(hash, objlist)
- for h in hashed[1:]:
- if h != hashed[0]:
- self.fail("hashed values differ: %r" % (objlist,))
- def test_numeric_literals(self):
- self.same_hash(1, 1L, 1.0, 1.0+0.0j)
- self.same_hash(0, 0L, 0.0, 0.0+0.0j)
- self.same_hash(-1, -1L, -1.0, -1.0+0.0j)
- self.same_hash(-2, -2L, -2.0, -2.0+0.0j)
- def test_coerced_integers(self):
- self.same_hash(int(1), long(1), float(1), complex(1),
- int('1'), float('1.0'))
- self.same_hash(int(-2**31), long(-2**31), float(-2**31))
- self.same_hash(int(1-2**31), long(1-2**31), float(1-2**31))
- self.same_hash(int(2**31-1), long(2**31-1), float(2**31-1))
- # for 64-bit platforms
- self.same_hash(int(2**31), long(2**31), float(2**31))
- self.same_hash(int(-2**63), long(-2**63), float(-2**63))
- self.same_hash(int(1-2**63), long(1-2**63))
- self.same_hash(int(2**63-1), long(2**63-1))
- def test_coerced_floats(self):
- self.same_hash(long(1.23e300), float(1.23e300))
- self.same_hash(float(0.5), complex(0.5, 0.0))
- _default_hash = object.__hash__
- class DefaultHash(object): pass
- _FIXED_HASH_VALUE = 42
- class FixedHash(object):
- def __hash__(self):
- return _FIXED_HASH_VALUE
- class OnlyEquality(object):
- def __eq__(self, other):
- return self is other
- # Trick to suppress Py3k warning in 2.x
- __hash__ = None
- del OnlyEquality.__hash__
- class OnlyInequality(object):
- def __ne__(self, other):
- return self is not other
- class OnlyCmp(object):
- def __cmp__(self, other):
- return cmp(id(self), id(other))
- # Trick to suppress Py3k warning in 2.x
- __hash__ = None
- del OnlyCmp.__hash__
- class InheritedHashWithEquality(FixedHash, OnlyEquality): pass
- class InheritedHashWithInequality(FixedHash, OnlyInequality): pass
- class InheritedHashWithCmp(FixedHash, OnlyCmp): pass
- class NoHash(object):
- __hash__ = None
- class HashInheritanceTestCase(unittest.TestCase):
- default_expected = [object(),
- DefaultHash(),
- OnlyEquality(),
- OnlyInequality(),
- OnlyCmp(),
- ]
- fixed_expected = [FixedHash(),
- InheritedHashWithEquality(),
- InheritedHashWithInequality(),
- InheritedHashWithCmp(),
- ]
- error_expected = [NoHash()]
- def test_default_hash(self):
- for obj in self.default_expected:
- self.assertEqual(hash(obj), _default_hash(obj))
- def test_fixed_hash(self):
- for obj in self.fixed_expected:
- self.assertEqual(hash(obj), _FIXED_HASH_VALUE)
- def test_error_hash(self):
- for obj in self.error_expected:
- self.assertRaises(TypeError, hash, obj)
- def test_hashable(self):
- objects = (self.default_expected +
- self.fixed_expected)
- for obj in objects:
- self.assert_(isinstance(obj, Hashable), repr(obj))
- def test_not_hashable(self):
- for obj in self.error_expected:
- self.assertFalse(isinstance(obj, Hashable), repr(obj))
- # Issue #4701: Check that some builtin types are correctly hashable
- # (This test only used to fail in Python 3.0, but has been included
- # in 2.x along with the lazy call to PyType_Ready in PyObject_Hash)
- class DefaultIterSeq(object):
- seq = range(10)
- def __len__(self):
- return len(self.seq)
- def __getitem__(self, index):
- return self.seq[index]
- class HashBuiltinsTestCase(unittest.TestCase):
- hashes_to_check = [xrange(10),
- enumerate(xrange(10)),
- iter(DefaultIterSeq()),
- iter(lambda: 0, 0),
- ]
- def test_hashes(self):
- _default_hash = object.__hash__
- for obj in self.hashes_to_check:
- self.assertEqual(hash(obj), _default_hash(obj))
- def test_main():
- test_support.run_unittest(HashEqualityTestCase,
- HashInheritanceTestCase,
- HashBuiltinsTestCase)
- if __name__ == "__main__":
- test_main()