# 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)) | |
self.same_hash(long(2**63), float(2**63)) | |
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.assertIsInstance(obj, Hashable) | |
def test_not_hashable(self): | |
for obj in self.error_expected: | |
self.assertNotIsInstance(obj, Hashable) | |
# 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() |