# test the invariant that
# iff a==b then hash(a)==hash(b)
#
# Also test that hash implementations are inherited as expected
import os
import sys
import struct
import datetime
import unittest
import subprocess
from test import test_support
from collections import Hashable
IS_64BIT = (struct.calcsize('l') == 8)
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))
class HashRandomizationTests(unittest.TestCase):
# Each subclass should define a field "repr_", containing the repr() of
# an object to be tested
def get_hash_command(self, repr_):
return 'print(hash(%s))' % repr_
def get_hash(self, repr_, seed=None):
env = os.environ.copy()
if seed is not None:
env['PYTHONHASHSEED'] = str(seed)
else:
env.pop('PYTHONHASHSEED', None)
cmd_line = [sys.executable, '-c', self.get_hash_command(repr_)]
p = subprocess.Popen(cmd_line, stdin=subprocess.PIPE,
stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
env=env)
out, err = p.communicate()
out = test_support.strip_python_stderr(out)
return int(out.strip())
def test_randomized_hash(self):
# two runs should return different hashes
run1 = self.get_hash(self.repr_, seed='random')
run2 = self.get_hash(self.repr_, seed='random')
self.assertNotEqual(run1, run2)
class StringlikeHashRandomizationTests(HashRandomizationTests):
def test_null_hash(self):
# PYTHONHASHSEED=0 disables the randomized hash
if IS_64BIT:
known_hash_of_obj = 1453079729188098211
else:
known_hash_of_obj = -1600925533
# Randomization is disabled by default:
self.assertEqual(self.get_hash(self.repr_), known_hash_of_obj)
# It can also be disabled by setting the seed to 0:
self.assertEqual(self.get_hash(self.repr_, seed=0), known_hash_of_obj)
def test_fixed_hash(self):
# test a fixed seed for the randomized hash
# Note that all types share the same values:
if IS_64BIT:
if sys.byteorder == 'little':
h = -4410911502303878509
else:
h = -3570150969479994130
else:
if sys.byteorder == 'little':
h = -206076799
else:
h = -1024014457
self.assertEqual(self.get_hash(self.repr_, seed=42), h)
class StrHashRandomizationTests(StringlikeHashRandomizationTests):
repr_ = repr('abc')
def test_empty_string(self):
self.assertEqual(hash(""), 0)
class UnicodeHashRandomizationTests(StringlikeHashRandomizationTests):
repr_ = repr(u'abc')
def test_empty_string(self):
self.assertEqual(hash(u""), 0)
class BufferHashRandomizationTests(StringlikeHashRandomizationTests):
repr_ = 'buffer("abc")'
def test_empty_string(self):
self.assertEqual(hash(buffer("")), 0)
class DatetimeTests(HashRandomizationTests):
def get_hash_command(self, repr_):
return 'import datetime; print(hash(%s))' % repr_
class DatetimeDateTests(DatetimeTests):
repr_ = repr(datetime.date(1066, 10, 14))
class DatetimeDatetimeTests(DatetimeTests):
repr_ = repr(datetime.datetime(1, 2, 3, 4, 5, 6, 7))
class DatetimeTimeTests(DatetimeTests):
repr_ = repr(datetime.time(0))
def test_main():
test_support.run_unittest(HashEqualityTestCase,
HashInheritanceTestCase,
HashBuiltinsTestCase,
StrHashRandomizationTests,
UnicodeHashRandomizationTests,
BufferHashRandomizationTests,
DatetimeDateTests,
DatetimeDatetimeTests,
DatetimeTimeTests)
if __name__ == "__main__":
test_main()