cpython/Lib/test/test_hash.py

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# test the invariant that
# iff a==b then hash(a)==hash(b)
#
# Also test that hash implementations are inherited as expected
import datetime
import os
import sys
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import unittest
from test import support
from test.script_helper import assert_python_ok
from collections import Hashable
IS_64BIT = sys.maxsize > 2**32
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class HashEqualityTestCase(unittest.TestCase):
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def same_hash(self, *objlist):
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# Hash each object given and fail if
# the hash values are not all the same.
Merged revisions 56125-56153 via svnmerge from svn+ssh://pythondev@svn.python.org/python/branches/p3yk ........ r56127 | georg.brandl | 2007-06-30 09:32:49 +0200 (Sat, 30 Jun 2007) | 2 lines Fix a place where floor division would be in order. ........ r56135 | guido.van.rossum | 2007-07-01 06:13:54 +0200 (Sun, 01 Jul 2007) | 28 lines Make map() and filter() identical to itertools.imap() and .ifilter(), respectively. I fixed two bootstrap issues, due to the dynamic import of itertools: 1. Starting python requires that map() and filter() are not used until site.py has added build/lib.<arch> to sys.path. 2. Building python requires that setup.py and distutils and everything they use is free of map() and filter() calls. Beyond this, I only fixed the tests in test_builtin.py. Others, please help fixing the remaining tests that are now broken! The fixes are usually simple: a. map(None, X) -> list(X) b. map(F, X) -> list(map(F, X)) c. map(lambda x: F(x), X) -> [F(x) for x in X] d. filter(F, X) -> list(filter(F, X)) e. filter(lambda x: P(x), X) -> [x for x in X if P(x)] Someone, please also contribute a fixer for 2to3 to do this. It can leave map()/filter() calls alone that are already inside a list() or sorted() call or for-loop. Only in rare cases have I seen code that depends on map() of lists of different lengths going to the end of the longest, or on filter() of a string or tuple returning an object of the same type; these will need more thought to fix. ........ r56136 | guido.van.rossum | 2007-07-01 06:22:01 +0200 (Sun, 01 Jul 2007) | 3 lines Make it so that test_decimal fails instead of hangs, to help automated test runners. ........ r56139 | georg.brandl | 2007-07-01 18:20:58 +0200 (Sun, 01 Jul 2007) | 2 lines Fix a few test cases after the map->imap change. ........ r56142 | neal.norwitz | 2007-07-02 06:38:12 +0200 (Mon, 02 Jul 2007) | 1 line Get a bunch more tests passing after converting map/filter to return iterators. ........ r56147 | guido.van.rossum | 2007-07-02 15:32:02 +0200 (Mon, 02 Jul 2007) | 4 lines Fix the remaining failing unit tests (at least on OSX). Also tweaked urllib2 so it doesn't raise socket.gaierror when all network interfaces are turned off. ........
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hashed = list(map(hash, objlist))
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for h in hashed[1:]:
if h != hashed[0]:
self.fail("hashed values differ: %r" % (objlist,))
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def test_numeric_literals(self):
self.same_hash(1, 1, 1.0, 1.0+0.0j)
self.same_hash(0, 0.0, 0.0+0.0j)
self.same_hash(-1, -1.0, -1.0+0.0j)
self.same_hash(-2, -2.0, -2.0+0.0j)
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def test_coerced_integers(self):
self.same_hash(int(1), int(1), float(1), complex(1),
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int('1'), float('1.0'))
self.same_hash(int(-2**31), float(-2**31))
self.same_hash(int(1-2**31), float(1-2**31))
self.same_hash(int(2**31-1), float(2**31-1))
# for 64-bit platforms
self.same_hash(int(2**31), float(2**31))
self.same_hash(int(-2**63), float(-2**63))
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self.same_hash(int(2**63), float(2**63))
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def test_coerced_floats(self):
self.same_hash(int(1.23e300), float(1.23e300))
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self.same_hash(float(0.5), complex(0.5, 0.0))
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_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
class OnlyInequality(object):
def __ne__(self, other):
return self is not other
class InheritedHashWithEquality(FixedHash, OnlyEquality): pass
class InheritedHashWithInequality(FixedHash, OnlyInequality): pass
class NoHash(object):
__hash__ = None
class HashInheritanceTestCase(unittest.TestCase):
default_expected = [object(),
DefaultHash(),
OnlyInequality(),
]
fixed_expected = [FixedHash(),
InheritedHashWithEquality(),
InheritedHashWithInequality(),
]
error_expected = [NoHash(),
OnlyEquality(),
]
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
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 = [enumerate(range(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()
env['__cleanenv'] = True # signal to assert_python not to do a copy
# of os.environ on its own
if seed is not None:
env['PYTHONHASHSEED'] = str(seed)
else:
env.pop('PYTHONHASHSEED', None)
out = assert_python_ok(
'-c', self.get_hash_command(repr_),
**env)
stdout = out[1].strip()
return int(stdout)
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
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# Randomization is enabled by default:
self.assertNotEqual(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 BytesHashRandomizationTests(StringlikeHashRandomizationTests):
repr_ = repr(b'abc')
def test_empty_string(self):
self.assertEqual(hash(b""), 0)
class MemoryviewHashRandomizationTests(StringlikeHashRandomizationTests):
repr_ = "memoryview(b'abc')"
def test_empty_string(self):
self.assertEqual(hash(memoryview(b"")), 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():
support.run_unittest(HashEqualityTestCase,
HashInheritanceTestCase,
HashBuiltinsTestCase,
StrHashRandomizationTests,
BytesHashRandomizationTests,
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MemoryviewHashRandomizationTests,
DatetimeDateTests,
DatetimeDatetimeTests,
DatetimeTimeTests)
if __name__ == "__main__":
test_main()