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      1 """Tests for Lib/fractions.py."""
      2 
      3 from decimal import Decimal
      4 from test.test_support import run_unittest
      5 import math
      6 import numbers
      7 import operator
      8 import fractions
      9 import sys
     10 import unittest
     11 from copy import copy, deepcopy
     12 from cPickle import dumps, loads
     13 F = fractions.Fraction
     14 gcd = fractions.gcd
     15 
     16 # decorator for skipping tests on non-IEEE 754 platforms
     17 requires_IEEE_754 = unittest.skipUnless(
     18     float.__getformat__("double").startswith("IEEE"),
     19     "test requires IEEE 754 doubles")
     20 
     21 class DummyFloat(object):
     22     """Dummy float class for testing comparisons with Fractions"""
     23 
     24     def __init__(self, value):
     25         if not isinstance(value, float):
     26             raise TypeError("DummyFloat can only be initialized from float")
     27         self.value = value
     28 
     29     def _richcmp(self, other, op):
     30         if isinstance(other, numbers.Rational):
     31             return op(F.from_float(self.value), other)
     32         elif isinstance(other, DummyFloat):
     33             return op(self.value, other.value)
     34         else:
     35             return NotImplemented
     36 
     37     def __eq__(self, other): return self._richcmp(other, operator.eq)
     38     def __le__(self, other): return self._richcmp(other, operator.le)
     39     def __lt__(self, other): return self._richcmp(other, operator.lt)
     40     def __ge__(self, other): return self._richcmp(other, operator.ge)
     41     def __gt__(self, other): return self._richcmp(other, operator.gt)
     42 
     43     # shouldn't be calling __float__ at all when doing comparisons
     44     def __float__(self):
     45         assert False, "__float__ should not be invoked for comparisons"
     46 
     47     # same goes for subtraction
     48     def __sub__(self, other):
     49         assert False, "__sub__ should not be invoked for comparisons"
     50     __rsub__ = __sub__
     51 
     52     # Silence Py3k warning
     53     __hash__ = None
     54 
     55 
     56 class DummyRational(object):
     57     """Test comparison of Fraction with a naive rational implementation."""
     58 
     59     def __init__(self, num, den):
     60         g = gcd(num, den)
     61         self.num = num // g
     62         self.den = den // g
     63 
     64     def __eq__(self, other):
     65         if isinstance(other, fractions.Fraction):
     66             return (self.num == other._numerator and
     67                     self.den == other._denominator)
     68         else:
     69             return NotImplemented
     70 
     71     def __lt__(self, other):
     72         return(self.num * other._denominator < self.den * other._numerator)
     73 
     74     def __gt__(self, other):
     75         return(self.num * other._denominator > self.den * other._numerator)
     76 
     77     def __le__(self, other):
     78         return(self.num * other._denominator <= self.den * other._numerator)
     79 
     80     def __ge__(self, other):
     81         return(self.num * other._denominator >= self.den * other._numerator)
     82 
     83     # this class is for testing comparisons; conversion to float
     84     # should never be used for a comparison, since it loses accuracy
     85     def __float__(self):
     86         assert False, "__float__ should not be invoked"
     87 
     88     # Silence Py3k warning
     89     __hash__ = None
     90 
     91 
     92 class DummyFraction(fractions.Fraction):
     93     """Dummy Fraction subclass for copy and deepcopy testing."""
     94 
     95 class GcdTest(unittest.TestCase):
     96 
     97     def testMisc(self):
     98         self.assertEqual(0, gcd(0, 0))
     99         self.assertEqual(1, gcd(1, 0))
    100         self.assertEqual(-1, gcd(-1, 0))
    101         self.assertEqual(1, gcd(0, 1))
    102         self.assertEqual(-1, gcd(0, -1))
    103         self.assertEqual(1, gcd(7, 1))
    104         self.assertEqual(-1, gcd(7, -1))
    105         self.assertEqual(1, gcd(-23, 15))
    106         self.assertEqual(12, gcd(120, 84))
    107         self.assertEqual(-12, gcd(84, -120))
    108 
    109 
    110 def _components(r):
    111     return (r.numerator, r.denominator)
    112 
    113 
    114 class FractionTest(unittest.TestCase):
    115 
    116     def assertTypedEquals(self, expected, actual):
    117         """Asserts that both the types and values are the same."""
    118         self.assertEqual(type(expected), type(actual))
    119         self.assertEqual(expected, actual)
    120 
    121     def assertRaisesMessage(self, exc_type, message,
    122                             callable, *args, **kwargs):
    123         """Asserts that callable(*args, **kwargs) raises exc_type(message)."""
    124         try:
    125             callable(*args, **kwargs)
    126         except exc_type, e:
    127             self.assertEqual(message, str(e))
    128         else:
    129             self.fail("%s not raised" % exc_type.__name__)
    130 
    131     def testInit(self):
    132         self.assertEqual((0, 1), _components(F()))
    133         self.assertEqual((7, 1), _components(F(7)))
    134         self.assertEqual((7, 3), _components(F(F(7, 3))))
    135 
    136         self.assertEqual((-1, 1), _components(F(-1, 1)))
    137         self.assertEqual((-1, 1), _components(F(1, -1)))
    138         self.assertEqual((1, 1), _components(F(-2, -2)))
    139         self.assertEqual((1, 2), _components(F(5, 10)))
    140         self.assertEqual((7, 15), _components(F(7, 15)))
    141         self.assertEqual((10**23, 1), _components(F(10**23)))
    142 
    143         self.assertEqual((3, 77), _components(F(F(3, 7), 11)))
    144         self.assertEqual((-9, 5), _components(F(2, F(-10, 9))))
    145         self.assertEqual((2486, 2485), _components(F(F(22, 7), F(355, 113))))
    146 
    147         self.assertRaisesMessage(ZeroDivisionError, "Fraction(12, 0)",
    148                                  F, 12, 0)
    149         self.assertRaises(TypeError, F, 1.5 + 3j)
    150 
    151         self.assertRaises(TypeError, F, "3/2", 3)
    152         self.assertRaises(TypeError, F, 3, 0j)
    153         self.assertRaises(TypeError, F, 3, 1j)
    154 
    155     @requires_IEEE_754
    156     def testInitFromFloat(self):
    157         self.assertEqual((5, 2), _components(F(2.5)))
    158         self.assertEqual((0, 1), _components(F(-0.0)))
    159         self.assertEqual((3602879701896397, 36028797018963968),
    160                          _components(F(0.1)))
    161         self.assertRaises(TypeError, F, float('nan'))
    162         self.assertRaises(TypeError, F, float('inf'))
    163         self.assertRaises(TypeError, F, float('-inf'))
    164 
    165     def testInitFromDecimal(self):
    166         self.assertEqual((11, 10),
    167                          _components(F(Decimal('1.1'))))
    168         self.assertEqual((7, 200),
    169                          _components(F(Decimal('3.5e-2'))))
    170         self.assertEqual((0, 1),
    171                          _components(F(Decimal('.000e20'))))
    172         self.assertRaises(TypeError, F, Decimal('nan'))
    173         self.assertRaises(TypeError, F, Decimal('snan'))
    174         self.assertRaises(TypeError, F, Decimal('inf'))
    175         self.assertRaises(TypeError, F, Decimal('-inf'))
    176 
    177     def testFromString(self):
    178         self.assertEqual((5, 1), _components(F("5")))
    179         self.assertEqual((3, 2), _components(F("3/2")))
    180         self.assertEqual((3, 2), _components(F(" \n  +3/2")))
    181         self.assertEqual((-3, 2), _components(F("-3/2  ")))
    182         self.assertEqual((13, 2), _components(F("    013/02 \n  ")))
    183         self.assertEqual((13, 2), _components(F(u"    013/02 \n  ")))
    184 
    185         self.assertEqual((16, 5), _components(F(" 3.2 ")))
    186         self.assertEqual((-16, 5), _components(F(u" -3.2 ")))
    187         self.assertEqual((-3, 1), _components(F(u" -3. ")))
    188         self.assertEqual((3, 5), _components(F(u" .6 ")))
    189         self.assertEqual((1, 3125), _components(F("32.e-5")))
    190         self.assertEqual((1000000, 1), _components(F("1E+06")))
    191         self.assertEqual((-12300, 1), _components(F("-1.23e4")))
    192         self.assertEqual((0, 1), _components(F(" .0e+0\t")))
    193         self.assertEqual((0, 1), _components(F("-0.000e0")))
    194 
    195 
    196         self.assertRaisesMessage(
    197             ZeroDivisionError, "Fraction(3, 0)",
    198             F, "3/0")
    199         self.assertRaisesMessage(
    200             ValueError, "Invalid literal for Fraction: '3/'",
    201             F, "3/")
    202         self.assertRaisesMessage(
    203             ValueError, "Invalid literal for Fraction: '/2'",
    204             F, "/2")
    205         self.assertRaisesMessage(
    206             ValueError, "Invalid literal for Fraction: '3 /2'",
    207             F, "3 /2")
    208         self.assertRaisesMessage(
    209             # Denominators don't need a sign.
    210             ValueError, "Invalid literal for Fraction: '3/+2'",
    211             F, "3/+2")
    212         self.assertRaisesMessage(
    213             # Imitate float's parsing.
    214             ValueError, "Invalid literal for Fraction: '+ 3/2'",
    215             F, "+ 3/2")
    216         self.assertRaisesMessage(
    217             # Avoid treating '.' as a regex special character.
    218             ValueError, "Invalid literal for Fraction: '3a2'",
    219             F, "3a2")
    220         self.assertRaisesMessage(
    221             # Don't accept combinations of decimals and fractions.
    222             ValueError, "Invalid literal for Fraction: '3/7.2'",
    223             F, "3/7.2")
    224         self.assertRaisesMessage(
    225             # Don't accept combinations of decimals and fractions.
    226             ValueError, "Invalid literal for Fraction: '3.2/7'",
    227             F, "3.2/7")
    228         self.assertRaisesMessage(
    229             # Allow 3. and .3, but not .
    230             ValueError, "Invalid literal for Fraction: '.'",
    231             F, ".")
    232 
    233     def testImmutable(self):
    234         r = F(7, 3)
    235         r.__init__(2, 15)
    236         self.assertEqual((7, 3), _components(r))
    237 
    238         self.assertRaises(AttributeError, setattr, r, 'numerator', 12)
    239         self.assertRaises(AttributeError, setattr, r, 'denominator', 6)
    240         self.assertEqual((7, 3), _components(r))
    241 
    242         # But if you _really_ need to:
    243         r._numerator = 4
    244         r._denominator = 2
    245         self.assertEqual((4, 2), _components(r))
    246         # Which breaks some important operations:
    247         self.assertNotEqual(F(4, 2), r)
    248 
    249     def testFromFloat(self):
    250         self.assertRaises(TypeError, F.from_float, 3+4j)
    251         self.assertEqual((10, 1), _components(F.from_float(10)))
    252         bigint = 1234567890123456789
    253         self.assertEqual((bigint, 1), _components(F.from_float(bigint)))
    254         self.assertEqual((0, 1), _components(F.from_float(-0.0)))
    255         self.assertEqual((10, 1), _components(F.from_float(10.0)))
    256         self.assertEqual((-5, 2), _components(F.from_float(-2.5)))
    257         self.assertEqual((99999999999999991611392, 1),
    258                          _components(F.from_float(1e23)))
    259         self.assertEqual(float(10**23), float(F.from_float(1e23)))
    260         self.assertEqual((3602879701896397, 1125899906842624),
    261                          _components(F.from_float(3.2)))
    262         self.assertEqual(3.2, float(F.from_float(3.2)))
    263 
    264         inf = 1e1000
    265         nan = inf - inf
    266         self.assertRaisesMessage(
    267             TypeError, "Cannot convert inf to Fraction.",
    268             F.from_float, inf)
    269         self.assertRaisesMessage(
    270             TypeError, "Cannot convert -inf to Fraction.",
    271             F.from_float, -inf)
    272         self.assertRaisesMessage(
    273             TypeError, "Cannot convert nan to Fraction.",
    274             F.from_float, nan)
    275 
    276     def testFromDecimal(self):
    277         self.assertRaises(TypeError, F.from_decimal, 3+4j)
    278         self.assertEqual(F(10, 1), F.from_decimal(10))
    279         self.assertEqual(F(0), F.from_decimal(Decimal("-0")))
    280         self.assertEqual(F(5, 10), F.from_decimal(Decimal("0.5")))
    281         self.assertEqual(F(5, 1000), F.from_decimal(Decimal("5e-3")))
    282         self.assertEqual(F(5000), F.from_decimal(Decimal("5e3")))
    283         self.assertEqual(1 - F(1, 10**30),
    284                          F.from_decimal(Decimal("0." + "9" * 30)))
    285 
    286         self.assertRaisesMessage(
    287             TypeError, "Cannot convert Infinity to Fraction.",
    288             F.from_decimal, Decimal("inf"))
    289         self.assertRaisesMessage(
    290             TypeError, "Cannot convert -Infinity to Fraction.",
    291             F.from_decimal, Decimal("-inf"))
    292         self.assertRaisesMessage(
    293             TypeError, "Cannot convert NaN to Fraction.",
    294             F.from_decimal, Decimal("nan"))
    295         self.assertRaisesMessage(
    296             TypeError, "Cannot convert sNaN to Fraction.",
    297             F.from_decimal, Decimal("snan"))
    298 
    299     def testLimitDenominator(self):
    300         rpi = F('3.1415926535897932')
    301         self.assertEqual(rpi.limit_denominator(10000), F(355, 113))
    302         self.assertEqual(-rpi.limit_denominator(10000), F(-355, 113))
    303         self.assertEqual(rpi.limit_denominator(113), F(355, 113))
    304         self.assertEqual(rpi.limit_denominator(112), F(333, 106))
    305         self.assertEqual(F(201, 200).limit_denominator(100), F(1))
    306         self.assertEqual(F(201, 200).limit_denominator(101), F(102, 101))
    307         self.assertEqual(F(0).limit_denominator(10000), F(0))
    308         for i in (0, -1):
    309             self.assertRaisesMessage(
    310                 ValueError, "max_denominator should be at least 1",
    311                 F(1).limit_denominator, i)
    312 
    313     def testConversions(self):
    314         self.assertTypedEquals(-1, math.trunc(F(-11, 10)))
    315         self.assertTypedEquals(-1, int(F(-11, 10)))
    316         self.assertTypedEquals(1, math.trunc(F(11, 10)))
    317         self.assertEqual(False, bool(F(0, 1)))
    318         self.assertEqual(True, bool(F(3, 2)))
    319         self.assertTypedEquals(0.1, float(F(1, 10)))
    320 
    321         # Check that __float__ isn't implemented by converting the
    322         # numerator and denominator to float before dividing.
    323         self.assertRaises(OverflowError, float, long('2'*400+'7'))
    324         self.assertAlmostEqual(2.0/3,
    325                                 float(F(long('2'*400+'7'), long('3'*400+'1'))))
    326 
    327         self.assertTypedEquals(0.1+0j, complex(F(1,10)))
    328 
    329 
    330     def testArithmetic(self):
    331         self.assertEqual(F(1, 2), F(1, 10) + F(2, 5))
    332         self.assertEqual(F(-3, 10), F(1, 10) - F(2, 5))
    333         self.assertEqual(F(1, 25), F(1, 10) * F(2, 5))
    334         self.assertEqual(F(1, 4), F(1, 10) / F(2, 5))
    335         self.assertTypedEquals(2, F(9, 10) // F(2, 5))
    336         self.assertTypedEquals(10**23, F(10**23, 1) // F(1))
    337         self.assertEqual(F(2, 3), F(-7, 3) % F(3, 2))
    338         self.assertEqual(F(8, 27), F(2, 3) ** F(3))
    339         self.assertEqual(F(27, 8), F(2, 3) ** F(-3))
    340         self.assertTypedEquals(2.0, F(4) ** F(1, 2))
    341         self.assertEqual(F(1, 1), +F(1, 1))
    342         # Will return 1j in 3.0:
    343         self.assertRaises(ValueError, pow, F(-1), F(1, 2))
    344 
    345     def testMixedArithmetic(self):
    346         self.assertTypedEquals(F(11, 10), F(1, 10) + 1)
    347         self.assertTypedEquals(1.1, F(1, 10) + 1.0)
    348         self.assertTypedEquals(1.1 + 0j, F(1, 10) + (1.0 + 0j))
    349         self.assertTypedEquals(F(11, 10), 1 + F(1, 10))
    350         self.assertTypedEquals(1.1, 1.0 + F(1, 10))
    351         self.assertTypedEquals(1.1 + 0j, (1.0 + 0j) + F(1, 10))
    352 
    353         self.assertTypedEquals(F(-9, 10), F(1, 10) - 1)
    354         self.assertTypedEquals(-0.9, F(1, 10) - 1.0)
    355         self.assertTypedEquals(-0.9 + 0j, F(1, 10) - (1.0 + 0j))
    356         self.assertTypedEquals(F(9, 10), 1 - F(1, 10))
    357         self.assertTypedEquals(0.9, 1.0 - F(1, 10))
    358         self.assertTypedEquals(0.9 + 0j, (1.0 + 0j) - F(1, 10))
    359 
    360         self.assertTypedEquals(F(1, 10), F(1, 10) * 1)
    361         self.assertTypedEquals(0.1, F(1, 10) * 1.0)
    362         self.assertTypedEquals(0.1 + 0j, F(1, 10) * (1.0 + 0j))
    363         self.assertTypedEquals(F(1, 10), 1 * F(1, 10))
    364         self.assertTypedEquals(0.1, 1.0 * F(1, 10))
    365         self.assertTypedEquals(0.1 + 0j, (1.0 + 0j) * F(1, 10))
    366 
    367         self.assertTypedEquals(F(1, 10), F(1, 10) / 1)
    368         self.assertTypedEquals(0.1, F(1, 10) / 1.0)
    369         self.assertTypedEquals(0.1 + 0j, F(1, 10) / (1.0 + 0j))
    370         self.assertTypedEquals(F(10, 1), 1 / F(1, 10))
    371         self.assertTypedEquals(10.0, 1.0 / F(1, 10))
    372         self.assertTypedEquals(10.0 + 0j, (1.0 + 0j) / F(1, 10))
    373 
    374         self.assertTypedEquals(0, F(1, 10) // 1)
    375         self.assertTypedEquals(0.0, F(1, 10) // 1.0)
    376         self.assertTypedEquals(10, 1 // F(1, 10))
    377         self.assertTypedEquals(10**23, 10**22 // F(1, 10))
    378         self.assertTypedEquals(10.0, 1.0 // F(1, 10))
    379 
    380         self.assertTypedEquals(F(1, 10), F(1, 10) % 1)
    381         self.assertTypedEquals(0.1, F(1, 10) % 1.0)
    382         self.assertTypedEquals(F(0, 1), 1 % F(1, 10))
    383         self.assertTypedEquals(0.0, 1.0 % F(1, 10))
    384 
    385         # No need for divmod since we don't override it.
    386 
    387         # ** has more interesting conversion rules.
    388         self.assertTypedEquals(F(100, 1), F(1, 10) ** -2)
    389         self.assertTypedEquals(F(100, 1), F(10, 1) ** 2)
    390         self.assertTypedEquals(0.1, F(1, 10) ** 1.0)
    391         self.assertTypedEquals(0.1 + 0j, F(1, 10) ** (1.0 + 0j))
    392         self.assertTypedEquals(4 , 2 ** F(2, 1))
    393         # Will return 1j in 3.0:
    394         self.assertRaises(ValueError, pow, (-1), F(1, 2))
    395         self.assertTypedEquals(F(1, 4) , 2 ** F(-2, 1))
    396         self.assertTypedEquals(2.0 , 4 ** F(1, 2))
    397         self.assertTypedEquals(0.25, 2.0 ** F(-2, 1))
    398         self.assertTypedEquals(1.0 + 0j, (1.0 + 0j) ** F(1, 10))
    399 
    400     def testMixingWithDecimal(self):
    401         # Decimal refuses mixed comparisons.
    402         self.assertRaisesMessage(
    403             TypeError,
    404             "unsupported operand type(s) for +: 'Fraction' and 'Decimal'",
    405             operator.add, F(3,11), Decimal('3.1415926'))
    406         self.assertRaisesMessage(
    407             TypeError,
    408             "unsupported operand type(s) for +: 'Decimal' and 'Fraction'",
    409             operator.add, Decimal('3.1415926'), F(3,11))
    410         self.assertNotEqual(F(5, 2), Decimal('2.5'))
    411 
    412     def testComparisons(self):
    413         self.assertTrue(F(1, 2) < F(2, 3))
    414         self.assertFalse(F(1, 2) < F(1, 2))
    415         self.assertTrue(F(1, 2) <= F(2, 3))
    416         self.assertTrue(F(1, 2) <= F(1, 2))
    417         self.assertFalse(F(2, 3) <= F(1, 2))
    418         self.assertTrue(F(1, 2) == F(1, 2))
    419         self.assertFalse(F(1, 2) == F(1, 3))
    420         self.assertFalse(F(1, 2) != F(1, 2))
    421         self.assertTrue(F(1, 2) != F(1, 3))
    422 
    423     def testComparisonsDummyRational(self):
    424         self.assertTrue(F(1, 2) == DummyRational(1, 2))
    425         self.assertTrue(DummyRational(1, 2) == F(1, 2))
    426         self.assertFalse(F(1, 2) == DummyRational(3, 4))
    427         self.assertFalse(DummyRational(3, 4) == F(1, 2))
    428 
    429         self.assertTrue(F(1, 2) < DummyRational(3, 4))
    430         self.assertFalse(F(1, 2) < DummyRational(1, 2))
    431         self.assertFalse(F(1, 2) < DummyRational(1, 7))
    432         self.assertFalse(F(1, 2) > DummyRational(3, 4))
    433         self.assertFalse(F(1, 2) > DummyRational(1, 2))
    434         self.assertTrue(F(1, 2) > DummyRational(1, 7))
    435         self.assertTrue(F(1, 2) <= DummyRational(3, 4))
    436         self.assertTrue(F(1, 2) <= DummyRational(1, 2))
    437         self.assertFalse(F(1, 2) <= DummyRational(1, 7))
    438         self.assertFalse(F(1, 2) >= DummyRational(3, 4))
    439         self.assertTrue(F(1, 2) >= DummyRational(1, 2))
    440         self.assertTrue(F(1, 2) >= DummyRational(1, 7))
    441 
    442         self.assertTrue(DummyRational(1, 2) < F(3, 4))
    443         self.assertFalse(DummyRational(1, 2) < F(1, 2))
    444         self.assertFalse(DummyRational(1, 2) < F(1, 7))
    445         self.assertFalse(DummyRational(1, 2) > F(3, 4))
    446         self.assertFalse(DummyRational(1, 2) > F(1, 2))
    447         self.assertTrue(DummyRational(1, 2) > F(1, 7))
    448         self.assertTrue(DummyRational(1, 2) <= F(3, 4))
    449         self.assertTrue(DummyRational(1, 2) <= F(1, 2))
    450         self.assertFalse(DummyRational(1, 2) <= F(1, 7))
    451         self.assertFalse(DummyRational(1, 2) >= F(3, 4))
    452         self.assertTrue(DummyRational(1, 2) >= F(1, 2))
    453         self.assertTrue(DummyRational(1, 2) >= F(1, 7))
    454 
    455     def testComparisonsDummyFloat(self):
    456         x = DummyFloat(1./3.)
    457         y = F(1, 3)
    458         self.assertTrue(x != y)
    459         self.assertTrue(x < y or x > y)
    460         self.assertFalse(x == y)
    461         self.assertFalse(x <= y and x >= y)
    462         self.assertTrue(y != x)
    463         self.assertTrue(y < x or y > x)
    464         self.assertFalse(y == x)
    465         self.assertFalse(y <= x and y >= x)
    466 
    467     def testMixedLess(self):
    468         self.assertTrue(2 < F(5, 2))
    469         self.assertFalse(2 < F(4, 2))
    470         self.assertTrue(F(5, 2) < 3)
    471         self.assertFalse(F(4, 2) < 2)
    472 
    473         self.assertTrue(F(1, 2) < 0.6)
    474         self.assertFalse(F(1, 2) < 0.4)
    475         self.assertTrue(0.4 < F(1, 2))
    476         self.assertFalse(0.5 < F(1, 2))
    477 
    478         self.assertFalse(float('inf') < F(1, 2))
    479         self.assertTrue(float('-inf') < F(0, 10))
    480         self.assertFalse(float('nan') < F(-3, 7))
    481         self.assertTrue(F(1, 2) < float('inf'))
    482         self.assertFalse(F(17, 12) < float('-inf'))
    483         self.assertFalse(F(144, -89) < float('nan'))
    484 
    485     def testMixedLessEqual(self):
    486         self.assertTrue(0.5 <= F(1, 2))
    487         self.assertFalse(0.6 <= F(1, 2))
    488         self.assertTrue(F(1, 2) <= 0.5)
    489         self.assertFalse(F(1, 2) <= 0.4)
    490         self.assertTrue(2 <= F(4, 2))
    491         self.assertFalse(2 <= F(3, 2))
    492         self.assertTrue(F(4, 2) <= 2)
    493         self.assertFalse(F(5, 2) <= 2)
    494 
    495         self.assertFalse(float('inf') <= F(1, 2))
    496         self.assertTrue(float('-inf') <= F(0, 10))
    497         self.assertFalse(float('nan') <= F(-3, 7))
    498         self.assertTrue(F(1, 2) <= float('inf'))
    499         self.assertFalse(F(17, 12) <= float('-inf'))
    500         self.assertFalse(F(144, -89) <= float('nan'))
    501 
    502     def testBigFloatComparisons(self):
    503         # Because 10**23 can't be represented exactly as a float:
    504         self.assertFalse(F(10**23) == float(10**23))
    505         # The first test demonstrates why these are important.
    506         self.assertFalse(1e23 < float(F(math.trunc(1e23) + 1)))
    507         self.assertTrue(1e23 < F(math.trunc(1e23) + 1))
    508         self.assertFalse(1e23 <= F(math.trunc(1e23) - 1))
    509         self.assertTrue(1e23 > F(math.trunc(1e23) - 1))
    510         self.assertFalse(1e23 >= F(math.trunc(1e23) + 1))
    511 
    512     def testBigComplexComparisons(self):
    513         self.assertFalse(F(10**23) == complex(10**23))
    514         self.assertRaises(TypeError, operator.gt, F(10**23), complex(10**23))
    515         self.assertRaises(TypeError, operator.le, F(10**23), complex(10**23))
    516 
    517         x = F(3, 8)
    518         z = complex(0.375, 0.0)
    519         w = complex(0.375, 0.2)
    520         self.assertTrue(x == z)
    521         self.assertFalse(x != z)
    522         self.assertFalse(x == w)
    523         self.assertTrue(x != w)
    524         for op in operator.lt, operator.le, operator.gt, operator.ge:
    525             self.assertRaises(TypeError, op, x, z)
    526             self.assertRaises(TypeError, op, z, x)
    527             self.assertRaises(TypeError, op, x, w)
    528             self.assertRaises(TypeError, op, w, x)
    529 
    530     def testMixedEqual(self):
    531         self.assertTrue(0.5 == F(1, 2))
    532         self.assertFalse(0.6 == F(1, 2))
    533         self.assertTrue(F(1, 2) == 0.5)
    534         self.assertFalse(F(1, 2) == 0.4)
    535         self.assertTrue(2 == F(4, 2))
    536         self.assertFalse(2 == F(3, 2))
    537         self.assertTrue(F(4, 2) == 2)
    538         self.assertFalse(F(5, 2) == 2)
    539         self.assertFalse(F(5, 2) == float('nan'))
    540         self.assertFalse(float('nan') == F(3, 7))
    541         self.assertFalse(F(5, 2) == float('inf'))
    542         self.assertFalse(float('-inf') == F(2, 5))
    543 
    544     def testStringification(self):
    545         self.assertEqual("Fraction(7, 3)", repr(F(7, 3)))
    546         self.assertEqual("Fraction(6283185307, 2000000000)",
    547                          repr(F('3.1415926535')))
    548         self.assertEqual("Fraction(-1, 100000000000000000000)",
    549                          repr(F(1, -10**20)))
    550         self.assertEqual("7/3", str(F(7, 3)))
    551         self.assertEqual("7", str(F(7, 1)))
    552 
    553     def testHash(self):
    554         self.assertEqual(hash(2.5), hash(F(5, 2)))
    555         self.assertEqual(hash(10**50), hash(F(10**50)))
    556         self.assertNotEqual(hash(float(10**23)), hash(F(10**23)))
    557 
    558     def testApproximatePi(self):
    559         # Algorithm borrowed from
    560         # http://docs.python.org/lib/decimal-recipes.html
    561         three = F(3)
    562         lasts, t, s, n, na, d, da = 0, three, 3, 1, 0, 0, 24
    563         while abs(s - lasts) > F(1, 10**9):
    564             lasts = s
    565             n, na = n+na, na+8
    566             d, da = d+da, da+32
    567             t = (t * n) / d
    568             s += t
    569         self.assertAlmostEqual(math.pi, s)
    570 
    571     def testApproximateCos1(self):
    572         # Algorithm borrowed from
    573         # http://docs.python.org/lib/decimal-recipes.html
    574         x = F(1)
    575         i, lasts, s, fact, num, sign = 0, 0, F(1), 1, 1, 1
    576         while abs(s - lasts) > F(1, 10**9):
    577             lasts = s
    578             i += 2
    579             fact *= i * (i-1)
    580             num *= x * x
    581             sign *= -1
    582             s += num / fact * sign
    583         self.assertAlmostEqual(math.cos(1), s)
    584 
    585     def test_copy_deepcopy_pickle(self):
    586         r = F(13, 7)
    587         dr = DummyFraction(13, 7)
    588         self.assertEqual(r, loads(dumps(r)))
    589         self.assertEqual(id(r), id(copy(r)))
    590         self.assertEqual(id(r), id(deepcopy(r)))
    591         self.assertNotEqual(id(dr), id(copy(dr)))
    592         self.assertNotEqual(id(dr), id(deepcopy(dr)))
    593         self.assertTypedEquals(dr, copy(dr))
    594         self.assertTypedEquals(dr, deepcopy(dr))
    595 
    596     def test_slots(self):
    597         # Issue 4998
    598         r = F(13, 7)
    599         self.assertRaises(AttributeError, setattr, r, 'a', 10)
    600 
    601 def test_main():
    602     run_unittest(FractionTest, GcdTest)
    603 
    604 if __name__ == '__main__':
    605     test_main()
    606