Revision 070fae6d0ff49e63bfd5f2bdc66f8eb1df3b6557 authored by Christian Heimes on 02 July 2019, 18:39:42 UTC, committed by Ned Deily on 02 July 2019, 18:42:08 UTC


ssl.match_hostname() no longer accepts IPv4 addresses with additional text
after the address and only quad-dotted notation without trailing
whitespaces. Some inet_aton() implementations ignore whitespace and all data
after whitespace, e.g. '127.0.0.1 whatever'.

Short notations like '127.1' for '127.0.0.1' were already filtered out.

The bug was initially found by Dominik Czarnota and reported by Paul Kehrer.

Signed-off-by: Christian Heimes <christian@python.org>



https://bugs.python.org/issue37463
1 parent dcc0eb3
Raw File
test_float.py
import fractions
import operator
import os
import random
import sys
import struct
import time
import unittest

from test import support
from test.test_grammar import (VALID_UNDERSCORE_LITERALS,
                               INVALID_UNDERSCORE_LITERALS)
from math import isinf, isnan, copysign, ldexp

INF = float("inf")
NAN = float("nan")

have_getformat = hasattr(float, "__getformat__")
requires_getformat = unittest.skipUnless(have_getformat,
                                         "requires __getformat__")
requires_setformat = unittest.skipUnless(hasattr(float, "__setformat__"),
                                         "requires __setformat__")

#locate file with float format test values
test_dir = os.path.dirname(__file__) or os.curdir
format_testfile = os.path.join(test_dir, 'formatfloat_testcases.txt')

class FloatSubclass(float):
    pass

class OtherFloatSubclass(float):
    pass

class GeneralFloatCases(unittest.TestCase):

    def test_float(self):
        self.assertEqual(float(3.14), 3.14)
        self.assertEqual(float(314), 314.0)
        self.assertEqual(float("  3.14  "), 3.14)
        self.assertRaises(ValueError, float, "  0x3.1  ")
        self.assertRaises(ValueError, float, "  -0x3.p-1  ")
        self.assertRaises(ValueError, float, "  +0x3.p-1  ")
        self.assertRaises(ValueError, float, "++3.14")
        self.assertRaises(ValueError, float, "+-3.14")
        self.assertRaises(ValueError, float, "-+3.14")
        self.assertRaises(ValueError, float, "--3.14")
        self.assertRaises(ValueError, float, ".nan")
        self.assertRaises(ValueError, float, "+.inf")
        self.assertRaises(ValueError, float, ".")
        self.assertRaises(ValueError, float, "-.")
        self.assertRaises(TypeError, float, {})
        self.assertRaisesRegex(TypeError, "not 'dict'", float, {})
        # Lone surrogate
        self.assertRaises(ValueError, float, '\uD8F0')
        # check that we don't accept alternate exponent markers
        self.assertRaises(ValueError, float, "-1.7d29")
        self.assertRaises(ValueError, float, "3D-14")
        self.assertEqual(float("  \u0663.\u0661\u0664  "), 3.14)
        self.assertEqual(float("\N{EM SPACE}3.14\N{EN SPACE}"), 3.14)
        # extra long strings should not be a problem
        float(b'.' + b'1'*1000)
        float('.' + '1'*1000)
        # Invalid unicode string
        # See bpo-34087
        self.assertRaises(ValueError, float, '\u3053\u3093\u306b\u3061\u306f')

    def test_underscores(self):
        for lit in VALID_UNDERSCORE_LITERALS:
            if not any(ch in lit for ch in 'jJxXoObB'):
                self.assertEqual(float(lit), eval(lit))
                self.assertEqual(float(lit), float(lit.replace('_', '')))
        for lit in INVALID_UNDERSCORE_LITERALS:
            if lit in ('0_7', '09_99'):  # octals are not recognized here
                continue
            if not any(ch in lit for ch in 'jJxXoObB'):
                self.assertRaises(ValueError, float, lit)
        # Additional test cases; nan and inf are never valid as literals,
        # only in the float() constructor, but we don't allow underscores
        # in or around them.
        self.assertRaises(ValueError, float, '_NaN')
        self.assertRaises(ValueError, float, 'Na_N')
        self.assertRaises(ValueError, float, 'IN_F')
        self.assertRaises(ValueError, float, '-_INF')
        self.assertRaises(ValueError, float, '-INF_')
        # Check that we handle bytes values correctly.
        self.assertRaises(ValueError, float, b'0_.\xff9')

    def test_non_numeric_input_types(self):
        # Test possible non-numeric types for the argument x, including
        # subclasses of the explicitly documented accepted types.
        class CustomStr(str): pass
        class CustomBytes(bytes): pass
        class CustomByteArray(bytearray): pass

        factories = [
            bytes,
            bytearray,
            lambda b: CustomStr(b.decode()),
            CustomBytes,
            CustomByteArray,
            memoryview,
        ]
        try:
            from array import array
        except ImportError:
            pass
        else:
            factories.append(lambda b: array('B', b))

        for f in factories:
            x = f(b" 3.14  ")
            with self.subTest(type(x)):
                self.assertEqual(float(x), 3.14)
                with self.assertRaisesRegex(ValueError, "could not convert"):
                    float(f(b'A' * 0x10))

    def test_float_memoryview(self):
        self.assertEqual(float(memoryview(b'12.3')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.3\x00')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.3 ')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.3A')[1:4]), 2.3)
        self.assertEqual(float(memoryview(b'12.34')[1:4]), 2.3)

    def test_error_message(self):
        def check(s):
            with self.assertRaises(ValueError, msg='float(%r)' % (s,)) as cm:
                float(s)
            self.assertEqual(str(cm.exception),
                'could not convert string to float: %r' % (s,))

        check('\xbd')
        check('123\xbd')
        check('  123 456  ')
        check(b'  123 456  ')

        # non-ascii digits (error came from non-digit '!')
        check('\u0663\u0661\u0664!')
        # embedded NUL
        check('123\x00')
        check('123\x00 245')
        check('123\x00245')
        # byte string with embedded NUL
        check(b'123\x00')
        # non-UTF-8 byte string
        check(b'123\xa0')

    @support.run_with_locale('LC_NUMERIC', 'fr_FR', 'de_DE')
    def test_float_with_comma(self):
        # set locale to something that doesn't use '.' for the decimal point
        # float must not accept the locale specific decimal point but
        # it still has to accept the normal python syntax
        import locale
        if not locale.localeconv()['decimal_point'] == ',':
            self.skipTest('decimal_point is not ","')

        self.assertEqual(float("  3.14  "), 3.14)
        self.assertEqual(float("+3.14  "), 3.14)
        self.assertEqual(float("-3.14  "), -3.14)
        self.assertEqual(float(".14  "), .14)
        self.assertEqual(float("3.  "), 3.0)
        self.assertEqual(float("3.e3  "), 3000.0)
        self.assertEqual(float("3.2e3  "), 3200.0)
        self.assertEqual(float("2.5e-1  "), 0.25)
        self.assertEqual(float("5e-1"), 0.5)
        self.assertRaises(ValueError, float, "  3,14  ")
        self.assertRaises(ValueError, float, "  +3,14  ")
        self.assertRaises(ValueError, float, "  -3,14  ")
        self.assertRaises(ValueError, float, "  0x3.1  ")
        self.assertRaises(ValueError, float, "  -0x3.p-1  ")
        self.assertRaises(ValueError, float, "  +0x3.p-1  ")
        self.assertEqual(float("  25.e-1  "), 2.5)
        self.assertAlmostEqual(float("  .25e-1  "), .025)

    def test_floatconversion(self):
        # Make sure that calls to __float__() work properly
        class Foo1(object):
            def __float__(self):
                return 42.

        class Foo2(float):
            def __float__(self):
                return 42.

        class Foo3(float):
            def __new__(cls, value=0.):
                return float.__new__(cls, 2*value)

            def __float__(self):
                return self

        class Foo4(float):
            def __float__(self):
                return 42

        # Issue 5759: __float__ not called on str subclasses (though it is on
        # unicode subclasses).
        class FooStr(str):
            def __float__(self):
                return float(str(self)) + 1

        self.assertEqual(float(Foo1()), 42.)
        self.assertEqual(float(Foo2()), 42.)
        with self.assertWarns(DeprecationWarning):
            self.assertEqual(float(Foo3(21)), 42.)
        self.assertRaises(TypeError, float, Foo4(42))
        self.assertEqual(float(FooStr('8')), 9.)

        class Foo5:
            def __float__(self):
                return ""
        self.assertRaises(TypeError, time.sleep, Foo5())

        # Issue #24731
        class F:
            def __float__(self):
                return OtherFloatSubclass(42.)
        with self.assertWarns(DeprecationWarning):
            self.assertEqual(float(F()), 42.)
        with self.assertWarns(DeprecationWarning):
            self.assertIs(type(float(F())), float)
        with self.assertWarns(DeprecationWarning):
            self.assertEqual(FloatSubclass(F()), 42.)
        with self.assertWarns(DeprecationWarning):
            self.assertIs(type(FloatSubclass(F())), FloatSubclass)

    def test_keyword_args(self):
        with self.assertRaisesRegex(TypeError, 'keyword argument'):
            float(x='3.14')

    def test_is_integer(self):
        self.assertFalse((1.1).is_integer())
        self.assertTrue((1.).is_integer())
        self.assertFalse(float("nan").is_integer())
        self.assertFalse(float("inf").is_integer())

    def test_floatasratio(self):
        for f, ratio in [
                (0.875, (7, 8)),
                (-0.875, (-7, 8)),
                (0.0, (0, 1)),
                (11.5, (23, 2)),
            ]:
            self.assertEqual(f.as_integer_ratio(), ratio)

        for i in range(10000):
            f = random.random()
            f *= 10 ** random.randint(-100, 100)
            n, d = f.as_integer_ratio()
            self.assertEqual(float(n).__truediv__(d), f)

        R = fractions.Fraction
        self.assertEqual(R(0, 1),
                         R(*float(0.0).as_integer_ratio()))
        self.assertEqual(R(5, 2),
                         R(*float(2.5).as_integer_ratio()))
        self.assertEqual(R(1, 2),
                         R(*float(0.5).as_integer_ratio()))
        self.assertEqual(R(4728779608739021, 2251799813685248),
                         R(*float(2.1).as_integer_ratio()))
        self.assertEqual(R(-4728779608739021, 2251799813685248),
                         R(*float(-2.1).as_integer_ratio()))
        self.assertEqual(R(-2100, 1),
                         R(*float(-2100.0).as_integer_ratio()))

        self.assertRaises(OverflowError, float('inf').as_integer_ratio)
        self.assertRaises(OverflowError, float('-inf').as_integer_ratio)
        self.assertRaises(ValueError, float('nan').as_integer_ratio)

    def test_float_containment(self):
        floats = (INF, -INF, 0.0, 1.0, NAN)
        for f in floats:
            self.assertIn(f, [f])
            self.assertIn(f, (f,))
            self.assertIn(f, {f})
            self.assertIn(f, {f: None})
            self.assertEqual([f].count(f), 1, "[].count('%r') != 1" % f)
            self.assertIn(f, floats)

        for f in floats:
            # nonidentical containers, same type, same contents
            self.assertTrue([f] == [f], "[%r] != [%r]" % (f, f))
            self.assertTrue((f,) == (f,), "(%r,) != (%r,)" % (f, f))
            self.assertTrue({f} == {f}, "{%r} != {%r}" % (f, f))
            self.assertTrue({f : None} == {f: None}, "{%r : None} != "
                                                   "{%r : None}" % (f, f))

            # identical containers
            l, t, s, d = [f], (f,), {f}, {f: None}
            self.assertTrue(l == l, "[%r] not equal to itself" % f)
            self.assertTrue(t == t, "(%r,) not equal to itself" % f)
            self.assertTrue(s == s, "{%r} not equal to itself" % f)
            self.assertTrue(d == d, "{%r : None} not equal to itself" % f)

    def assertEqualAndEqualSign(self, a, b):
        # fail unless a == b and a and b have the same sign bit;
        # the only difference from assertEqual is that this test
        # distinguishes -0.0 and 0.0.
        self.assertEqual((a, copysign(1.0, a)), (b, copysign(1.0, b)))

    @support.requires_IEEE_754
    def test_float_mod(self):
        # Check behaviour of % operator for IEEE 754 special cases.
        # In particular, check signs of zeros.
        mod = operator.mod

        self.assertEqualAndEqualSign(mod(-1.0, 1.0), 0.0)
        self.assertEqualAndEqualSign(mod(-1e-100, 1.0), 1.0)
        self.assertEqualAndEqualSign(mod(-0.0, 1.0), 0.0)
        self.assertEqualAndEqualSign(mod(0.0, 1.0), 0.0)
        self.assertEqualAndEqualSign(mod(1e-100, 1.0), 1e-100)
        self.assertEqualAndEqualSign(mod(1.0, 1.0), 0.0)

        self.assertEqualAndEqualSign(mod(-1.0, -1.0), -0.0)
        self.assertEqualAndEqualSign(mod(-1e-100, -1.0), -1e-100)
        self.assertEqualAndEqualSign(mod(-0.0, -1.0), -0.0)
        self.assertEqualAndEqualSign(mod(0.0, -1.0), -0.0)
        self.assertEqualAndEqualSign(mod(1e-100, -1.0), -1.0)
        self.assertEqualAndEqualSign(mod(1.0, -1.0), -0.0)

    @support.requires_IEEE_754
    def test_float_pow(self):
        # test builtin pow and ** operator for IEEE 754 special cases.
        # Special cases taken from section F.9.4.4 of the C99 specification

        for pow_op in pow, operator.pow:
            # x**NAN is NAN for any x except 1
            self.assertTrue(isnan(pow_op(-INF, NAN)))
            self.assertTrue(isnan(pow_op(-2.0, NAN)))
            self.assertTrue(isnan(pow_op(-1.0, NAN)))
            self.assertTrue(isnan(pow_op(-0.5, NAN)))
            self.assertTrue(isnan(pow_op(-0.0, NAN)))
            self.assertTrue(isnan(pow_op(0.0, NAN)))
            self.assertTrue(isnan(pow_op(0.5, NAN)))
            self.assertTrue(isnan(pow_op(2.0, NAN)))
            self.assertTrue(isnan(pow_op(INF, NAN)))
            self.assertTrue(isnan(pow_op(NAN, NAN)))

            # NAN**y is NAN for any y except +-0
            self.assertTrue(isnan(pow_op(NAN, -INF)))
            self.assertTrue(isnan(pow_op(NAN, -2.0)))
            self.assertTrue(isnan(pow_op(NAN, -1.0)))
            self.assertTrue(isnan(pow_op(NAN, -0.5)))
            self.assertTrue(isnan(pow_op(NAN, 0.5)))
            self.assertTrue(isnan(pow_op(NAN, 1.0)))
            self.assertTrue(isnan(pow_op(NAN, 2.0)))
            self.assertTrue(isnan(pow_op(NAN, INF)))

            # (+-0)**y raises ZeroDivisionError for y a negative odd integer
            self.assertRaises(ZeroDivisionError, pow_op, -0.0, -1.0)
            self.assertRaises(ZeroDivisionError, pow_op, 0.0, -1.0)

            # (+-0)**y raises ZeroDivisionError for y finite and negative
            # but not an odd integer
            self.assertRaises(ZeroDivisionError, pow_op, -0.0, -2.0)
            self.assertRaises(ZeroDivisionError, pow_op, -0.0, -0.5)
            self.assertRaises(ZeroDivisionError, pow_op, 0.0, -2.0)
            self.assertRaises(ZeroDivisionError, pow_op, 0.0, -0.5)

            # (+-0)**y is +-0 for y a positive odd integer
            self.assertEqualAndEqualSign(pow_op(-0.0, 1.0), -0.0)
            self.assertEqualAndEqualSign(pow_op(0.0, 1.0), 0.0)

            # (+-0)**y is 0 for y finite and positive but not an odd integer
            self.assertEqualAndEqualSign(pow_op(-0.0, 0.5), 0.0)
            self.assertEqualAndEqualSign(pow_op(-0.0, 2.0), 0.0)
            self.assertEqualAndEqualSign(pow_op(0.0, 0.5), 0.0)
            self.assertEqualAndEqualSign(pow_op(0.0, 2.0), 0.0)

            # (-1)**+-inf is 1
            self.assertEqualAndEqualSign(pow_op(-1.0, -INF), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, INF), 1.0)

            # 1**y is 1 for any y, even if y is an infinity or nan
            self.assertEqualAndEqualSign(pow_op(1.0, -INF), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, -2.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, -1.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, -0.5), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, 0.5), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, 1.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, 2.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, INF), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, NAN), 1.0)

            # x**+-0 is 1 for any x, even if x is a zero, infinity, or nan
            self.assertEqualAndEqualSign(pow_op(-INF, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-2.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-0.5, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-0.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(0.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(0.5, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(2.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(INF, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(NAN, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-INF, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-2.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-0.5, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-0.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(0.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(0.5, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(2.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(INF, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(NAN, -0.0), 1.0)

            # x**y defers to complex pow for finite negative x and
            # non-integral y.
            self.assertEqual(type(pow_op(-2.0, -0.5)), complex)
            self.assertEqual(type(pow_op(-2.0, 0.5)), complex)
            self.assertEqual(type(pow_op(-1.0, -0.5)), complex)
            self.assertEqual(type(pow_op(-1.0, 0.5)), complex)
            self.assertEqual(type(pow_op(-0.5, -0.5)), complex)
            self.assertEqual(type(pow_op(-0.5, 0.5)), complex)

            # x**-INF is INF for abs(x) < 1
            self.assertEqualAndEqualSign(pow_op(-0.5, -INF), INF)
            self.assertEqualAndEqualSign(pow_op(-0.0, -INF), INF)
            self.assertEqualAndEqualSign(pow_op(0.0, -INF), INF)
            self.assertEqualAndEqualSign(pow_op(0.5, -INF), INF)

            # x**-INF is 0 for abs(x) > 1
            self.assertEqualAndEqualSign(pow_op(-INF, -INF), 0.0)
            self.assertEqualAndEqualSign(pow_op(-2.0, -INF), 0.0)
            self.assertEqualAndEqualSign(pow_op(2.0, -INF), 0.0)
            self.assertEqualAndEqualSign(pow_op(INF, -INF), 0.0)

            # x**INF is 0 for abs(x) < 1
            self.assertEqualAndEqualSign(pow_op(-0.5, INF), 0.0)
            self.assertEqualAndEqualSign(pow_op(-0.0, INF), 0.0)
            self.assertEqualAndEqualSign(pow_op(0.0, INF), 0.0)
            self.assertEqualAndEqualSign(pow_op(0.5, INF), 0.0)

            # x**INF is INF for abs(x) > 1
            self.assertEqualAndEqualSign(pow_op(-INF, INF), INF)
            self.assertEqualAndEqualSign(pow_op(-2.0, INF), INF)
            self.assertEqualAndEqualSign(pow_op(2.0, INF), INF)
            self.assertEqualAndEqualSign(pow_op(INF, INF), INF)

            # (-INF)**y is -0.0 for y a negative odd integer
            self.assertEqualAndEqualSign(pow_op(-INF, -1.0), -0.0)

            # (-INF)**y is 0.0 for y negative but not an odd integer
            self.assertEqualAndEqualSign(pow_op(-INF, -0.5), 0.0)
            self.assertEqualAndEqualSign(pow_op(-INF, -2.0), 0.0)

            # (-INF)**y is -INF for y a positive odd integer
            self.assertEqualAndEqualSign(pow_op(-INF, 1.0), -INF)

            # (-INF)**y is INF for y positive but not an odd integer
            self.assertEqualAndEqualSign(pow_op(-INF, 0.5), INF)
            self.assertEqualAndEqualSign(pow_op(-INF, 2.0), INF)

            # INF**y is INF for y positive
            self.assertEqualAndEqualSign(pow_op(INF, 0.5), INF)
            self.assertEqualAndEqualSign(pow_op(INF, 1.0), INF)
            self.assertEqualAndEqualSign(pow_op(INF, 2.0), INF)

            # INF**y is 0.0 for y negative
            self.assertEqualAndEqualSign(pow_op(INF, -2.0), 0.0)
            self.assertEqualAndEqualSign(pow_op(INF, -1.0), 0.0)
            self.assertEqualAndEqualSign(pow_op(INF, -0.5), 0.0)

            # basic checks not covered by the special cases above
            self.assertEqualAndEqualSign(pow_op(-2.0, -2.0), 0.25)
            self.assertEqualAndEqualSign(pow_op(-2.0, -1.0), -0.5)
            self.assertEqualAndEqualSign(pow_op(-2.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-2.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-2.0, 1.0), -2.0)
            self.assertEqualAndEqualSign(pow_op(-2.0, 2.0), 4.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, -2.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, -1.0), -1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, 1.0), -1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, 2.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(2.0, -2.0), 0.25)
            self.assertEqualAndEqualSign(pow_op(2.0, -1.0), 0.5)
            self.assertEqualAndEqualSign(pow_op(2.0, -0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(2.0, 0.0), 1.0)
            self.assertEqualAndEqualSign(pow_op(2.0, 1.0), 2.0)
            self.assertEqualAndEqualSign(pow_op(2.0, 2.0), 4.0)

            # 1 ** large and -1 ** large; some libms apparently
            # have problems with these
            self.assertEqualAndEqualSign(pow_op(1.0, -1e100), 1.0)
            self.assertEqualAndEqualSign(pow_op(1.0, 1e100), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, -1e100), 1.0)
            self.assertEqualAndEqualSign(pow_op(-1.0, 1e100), 1.0)

            # check sign for results that underflow to 0
            self.assertEqualAndEqualSign(pow_op(-2.0, -2000.0), 0.0)
            self.assertEqual(type(pow_op(-2.0, -2000.5)), complex)
            self.assertEqualAndEqualSign(pow_op(-2.0, -2001.0), -0.0)
            self.assertEqualAndEqualSign(pow_op(2.0, -2000.0), 0.0)
            self.assertEqualAndEqualSign(pow_op(2.0, -2000.5), 0.0)
            self.assertEqualAndEqualSign(pow_op(2.0, -2001.0), 0.0)
            self.assertEqualAndEqualSign(pow_op(-0.5, 2000.0), 0.0)
            self.assertEqual(type(pow_op(-0.5, 2000.5)), complex)
            self.assertEqualAndEqualSign(pow_op(-0.5, 2001.0), -0.0)
            self.assertEqualAndEqualSign(pow_op(0.5, 2000.0), 0.0)
            self.assertEqualAndEqualSign(pow_op(0.5, 2000.5), 0.0)
            self.assertEqualAndEqualSign(pow_op(0.5, 2001.0), 0.0)

            # check we don't raise an exception for subnormal results,
            # and validate signs.  Tests currently disabled, since
            # they fail on systems where a subnormal result from pow
            # is flushed to zero (e.g. Debian/ia64.)
            #self.assertTrue(0.0 < pow_op(0.5, 1048) < 1e-315)
            #self.assertTrue(0.0 < pow_op(-0.5, 1048) < 1e-315)
            #self.assertTrue(0.0 < pow_op(0.5, 1047) < 1e-315)
            #self.assertTrue(0.0 > pow_op(-0.5, 1047) > -1e-315)
            #self.assertTrue(0.0 < pow_op(2.0, -1048) < 1e-315)
            #self.assertTrue(0.0 < pow_op(-2.0, -1048) < 1e-315)
            #self.assertTrue(0.0 < pow_op(2.0, -1047) < 1e-315)
            #self.assertTrue(0.0 > pow_op(-2.0, -1047) > -1e-315)


@requires_setformat
class FormatFunctionsTestCase(unittest.TestCase):

    def setUp(self):
        self.save_formats = {'double':float.__getformat__('double'),
                             'float':float.__getformat__('float')}

    def tearDown(self):
        float.__setformat__('double', self.save_formats['double'])
        float.__setformat__('float', self.save_formats['float'])

    def test_getformat(self):
        self.assertIn(float.__getformat__('double'),
                      ['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
        self.assertIn(float.__getformat__('float'),
                      ['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
        self.assertRaises(ValueError, float.__getformat__, 'chicken')
        self.assertRaises(TypeError, float.__getformat__, 1)

    def test_setformat(self):
        for t in 'double', 'float':
            float.__setformat__(t, 'unknown')
            if self.save_formats[t] == 'IEEE, big-endian':
                self.assertRaises(ValueError, float.__setformat__,
                                  t, 'IEEE, little-endian')
            elif self.save_formats[t] == 'IEEE, little-endian':
                self.assertRaises(ValueError, float.__setformat__,
                                  t, 'IEEE, big-endian')
            else:
                self.assertRaises(ValueError, float.__setformat__,
                                  t, 'IEEE, big-endian')
                self.assertRaises(ValueError, float.__setformat__,
                                  t, 'IEEE, little-endian')
            self.assertRaises(ValueError, float.__setformat__,
                              t, 'chicken')
        self.assertRaises(ValueError, float.__setformat__,
                          'chicken', 'unknown')

BE_DOUBLE_INF = b'\x7f\xf0\x00\x00\x00\x00\x00\x00'
LE_DOUBLE_INF = bytes(reversed(BE_DOUBLE_INF))
BE_DOUBLE_NAN = b'\x7f\xf8\x00\x00\x00\x00\x00\x00'
LE_DOUBLE_NAN = bytes(reversed(BE_DOUBLE_NAN))

BE_FLOAT_INF = b'\x7f\x80\x00\x00'
LE_FLOAT_INF = bytes(reversed(BE_FLOAT_INF))
BE_FLOAT_NAN = b'\x7f\xc0\x00\x00'
LE_FLOAT_NAN = bytes(reversed(BE_FLOAT_NAN))

# on non-IEEE platforms, attempting to unpack a bit pattern
# representing an infinity or a NaN should raise an exception.

@requires_setformat
class UnknownFormatTestCase(unittest.TestCase):
    def setUp(self):
        self.save_formats = {'double':float.__getformat__('double'),
                             'float':float.__getformat__('float')}
        float.__setformat__('double', 'unknown')
        float.__setformat__('float', 'unknown')

    def tearDown(self):
        float.__setformat__('double', self.save_formats['double'])
        float.__setformat__('float', self.save_formats['float'])

    def test_double_specials_dont_unpack(self):
        for fmt, data in [('>d', BE_DOUBLE_INF),
                          ('>d', BE_DOUBLE_NAN),
                          ('<d', LE_DOUBLE_INF),
                          ('<d', LE_DOUBLE_NAN)]:
            self.assertRaises(ValueError, struct.unpack, fmt, data)

    def test_float_specials_dont_unpack(self):
        for fmt, data in [('>f', BE_FLOAT_INF),
                          ('>f', BE_FLOAT_NAN),
                          ('<f', LE_FLOAT_INF),
                          ('<f', LE_FLOAT_NAN)]:
            self.assertRaises(ValueError, struct.unpack, fmt, data)


# on an IEEE platform, all we guarantee is that bit patterns
# representing infinities or NaNs do not raise an exception; all else
# is accident (today).
# let's also try to guarantee that -0.0 and 0.0 don't get confused.

class IEEEFormatTestCase(unittest.TestCase):

    @support.requires_IEEE_754
    def test_double_specials_do_unpack(self):
        for fmt, data in [('>d', BE_DOUBLE_INF),
                          ('>d', BE_DOUBLE_NAN),
                          ('<d', LE_DOUBLE_INF),
                          ('<d', LE_DOUBLE_NAN)]:
            struct.unpack(fmt, data)

    @support.requires_IEEE_754
    def test_float_specials_do_unpack(self):
        for fmt, data in [('>f', BE_FLOAT_INF),
                          ('>f', BE_FLOAT_NAN),
                          ('<f', LE_FLOAT_INF),
                          ('<f', LE_FLOAT_NAN)]:
            struct.unpack(fmt, data)

    @support.requires_IEEE_754
    def test_serialized_float_rounding(self):
        from _testcapi import FLT_MAX
        self.assertEqual(struct.pack("<f", 3.40282356e38), struct.pack("<f", FLT_MAX))
        self.assertEqual(struct.pack("<f", -3.40282356e38), struct.pack("<f", -FLT_MAX))

class FormatTestCase(unittest.TestCase):

    def test_format(self):
        # these should be rewritten to use both format(x, spec) and
        # x.__format__(spec)

        self.assertEqual(format(0.0, 'f'), '0.000000')

        # the default is 'g', except for empty format spec
        self.assertEqual(format(0.0, ''), '0.0')
        self.assertEqual(format(0.01, ''), '0.01')
        self.assertEqual(format(0.01, 'g'), '0.01')

        # empty presentation type should format in the same way as str
        # (issue 5920)
        x = 100/7.
        self.assertEqual(format(x, ''), str(x))
        self.assertEqual(format(x, '-'), str(x))
        self.assertEqual(format(x, '>'), str(x))
        self.assertEqual(format(x, '2'), str(x))

        self.assertEqual(format(1.0, 'f'), '1.000000')

        self.assertEqual(format(-1.0, 'f'), '-1.000000')

        self.assertEqual(format( 1.0, ' f'), ' 1.000000')
        self.assertEqual(format(-1.0, ' f'), '-1.000000')
        self.assertEqual(format( 1.0, '+f'), '+1.000000')
        self.assertEqual(format(-1.0, '+f'), '-1.000000')

        # % formatting
        self.assertEqual(format(-1.0, '%'), '-100.000000%')

        # conversion to string should fail
        self.assertRaises(ValueError, format, 3.0, "s")

        # other format specifiers shouldn't work on floats,
        #  in particular int specifiers
        for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] +
                            [chr(x) for x in range(ord('A'), ord('Z')+1)]):
            if not format_spec in 'eEfFgGn%':
                self.assertRaises(ValueError, format, 0.0, format_spec)
                self.assertRaises(ValueError, format, 1.0, format_spec)
                self.assertRaises(ValueError, format, -1.0, format_spec)
                self.assertRaises(ValueError, format, 1e100, format_spec)
                self.assertRaises(ValueError, format, -1e100, format_spec)
                self.assertRaises(ValueError, format, 1e-100, format_spec)
                self.assertRaises(ValueError, format, -1e-100, format_spec)

        # issue 3382
        self.assertEqual(format(NAN, 'f'), 'nan')
        self.assertEqual(format(NAN, 'F'), 'NAN')
        self.assertEqual(format(INF, 'f'), 'inf')
        self.assertEqual(format(INF, 'F'), 'INF')

    @support.requires_IEEE_754
    def test_format_testfile(self):
        with open(format_testfile) as testfile:
            for line in testfile:
                if line.startswith('--'):
                    continue
                line = line.strip()
                if not line:
                    continue

                lhs, rhs = map(str.strip, line.split('->'))
                fmt, arg = lhs.split()
                self.assertEqual(fmt % float(arg), rhs)
                self.assertEqual(fmt % -float(arg), '-' + rhs)

    def test_issue5864(self):
        self.assertEqual(format(123.456, '.4'), '123.5')
        self.assertEqual(format(1234.56, '.4'), '1.235e+03')
        self.assertEqual(format(12345.6, '.4'), '1.235e+04')

    def test_issue35560(self):
        self.assertEqual(format(123.0, '00'), '123.0')
        self.assertEqual(format(123.34, '00f'), '123.340000')
        self.assertEqual(format(123.34, '00e'), '1.233400e+02')
        self.assertEqual(format(123.34, '00g'), '123.34')
        self.assertEqual(format(123.34, '00.10f'), '123.3400000000')
        self.assertEqual(format(123.34, '00.10e'), '1.2334000000e+02')
        self.assertEqual(format(123.34, '00.10g'), '123.34')
        self.assertEqual(format(123.34, '01f'), '123.340000')

        self.assertEqual(format(-123.0, '00'), '-123.0')
        self.assertEqual(format(-123.34, '00f'), '-123.340000')
        self.assertEqual(format(-123.34, '00e'), '-1.233400e+02')
        self.assertEqual(format(-123.34, '00g'), '-123.34')
        self.assertEqual(format(-123.34, '00.10f'), '-123.3400000000')
        self.assertEqual(format(-123.34, '00.10f'), '-123.3400000000')
        self.assertEqual(format(-123.34, '00.10e'), '-1.2334000000e+02')
        self.assertEqual(format(-123.34, '00.10g'), '-123.34')

class ReprTestCase(unittest.TestCase):
    def test_repr(self):
        floats_file = open(os.path.join(os.path.split(__file__)[0],
                           'floating_points.txt'))
        for line in floats_file:
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            v = eval(line)
            self.assertEqual(v, eval(repr(v)))
        floats_file.close()

    @unittest.skipUnless(getattr(sys, 'float_repr_style', '') == 'short',
                         "applies only when using short float repr style")
    def test_short_repr(self):
        # test short float repr introduced in Python 3.1.  One aspect
        # of this repr is that we get some degree of str -> float ->
        # str roundtripping.  In particular, for any numeric string
        # containing 15 or fewer significant digits, those exact same
        # digits (modulo trailing zeros) should appear in the output.
        # No more repr(0.03) -> "0.029999999999999999"!

        test_strings = [
            # output always includes *either* a decimal point and at
            # least one digit after that point, or an exponent.
            '0.0',
            '1.0',
            '0.01',
            '0.02',
            '0.03',
            '0.04',
            '0.05',
            '1.23456789',
            '10.0',
            '100.0',
            # values >= 1e16 get an exponent...
            '1000000000000000.0',
            '9999999999999990.0',
            '1e+16',
            '1e+17',
            # ... and so do values < 1e-4
            '0.001',
            '0.001001',
            '0.00010000000000001',
            '0.0001',
            '9.999999999999e-05',
            '1e-05',
            # values designed to provoke failure if the FPU rounding
            # precision isn't set correctly
            '8.72293771110361e+25',
            '7.47005307342313e+26',
            '2.86438000439698e+28',
            '8.89142905246179e+28',
            '3.08578087079232e+35',
            ]

        for s in test_strings:
            negs = '-'+s
            self.assertEqual(s, repr(float(s)))
            self.assertEqual(negs, repr(float(negs)))
            # Since Python 3.2, repr and str are identical
            self.assertEqual(repr(float(s)), str(float(s)))
            self.assertEqual(repr(float(negs)), str(float(negs)))

@support.requires_IEEE_754
class RoundTestCase(unittest.TestCase):

    def test_inf_nan(self):
        self.assertRaises(OverflowError, round, INF)
        self.assertRaises(OverflowError, round, -INF)
        self.assertRaises(ValueError, round, NAN)
        self.assertRaises(TypeError, round, INF, 0.0)
        self.assertRaises(TypeError, round, -INF, 1.0)
        self.assertRaises(TypeError, round, NAN, "ceci n'est pas un integer")
        self.assertRaises(TypeError, round, -0.0, 1j)

    def test_large_n(self):
        for n in [324, 325, 400, 2**31-1, 2**31, 2**32, 2**100]:
            self.assertEqual(round(123.456, n), 123.456)
            self.assertEqual(round(-123.456, n), -123.456)
            self.assertEqual(round(1e300, n), 1e300)
            self.assertEqual(round(1e-320, n), 1e-320)
        self.assertEqual(round(1e150, 300), 1e150)
        self.assertEqual(round(1e300, 307), 1e300)
        self.assertEqual(round(-3.1415, 308), -3.1415)
        self.assertEqual(round(1e150, 309), 1e150)
        self.assertEqual(round(1.4e-315, 315), 1e-315)

    def test_small_n(self):
        for n in [-308, -309, -400, 1-2**31, -2**31, -2**31-1, -2**100]:
            self.assertEqual(round(123.456, n), 0.0)
            self.assertEqual(round(-123.456, n), -0.0)
            self.assertEqual(round(1e300, n), 0.0)
            self.assertEqual(round(1e-320, n), 0.0)

    def test_overflow(self):
        self.assertRaises(OverflowError, round, 1.6e308, -308)
        self.assertRaises(OverflowError, round, -1.7e308, -308)

    @unittest.skipUnless(getattr(sys, 'float_repr_style', '') == 'short',
                         "applies only when using short float repr style")
    def test_previous_round_bugs(self):
        # particular cases that have occurred in bug reports
        self.assertEqual(round(562949953421312.5, 1),
                          562949953421312.5)
        self.assertEqual(round(56294995342131.5, 3),
                         56294995342131.5)
        # round-half-even
        self.assertEqual(round(25.0, -1), 20.0)
        self.assertEqual(round(35.0, -1), 40.0)
        self.assertEqual(round(45.0, -1), 40.0)
        self.assertEqual(round(55.0, -1), 60.0)
        self.assertEqual(round(65.0, -1), 60.0)
        self.assertEqual(round(75.0, -1), 80.0)
        self.assertEqual(round(85.0, -1), 80.0)
        self.assertEqual(round(95.0, -1), 100.0)

    @unittest.skipUnless(getattr(sys, 'float_repr_style', '') == 'short',
                         "applies only when using short float repr style")
    def test_matches_float_format(self):
        # round should give the same results as float formatting
        for i in range(500):
            x = i/1000.
            self.assertEqual(float(format(x, '.0f')), round(x, 0))
            self.assertEqual(float(format(x, '.1f')), round(x, 1))
            self.assertEqual(float(format(x, '.2f')), round(x, 2))
            self.assertEqual(float(format(x, '.3f')), round(x, 3))

        for i in range(5, 5000, 10):
            x = i/1000.
            self.assertEqual(float(format(x, '.0f')), round(x, 0))
            self.assertEqual(float(format(x, '.1f')), round(x, 1))
            self.assertEqual(float(format(x, '.2f')), round(x, 2))
            self.assertEqual(float(format(x, '.3f')), round(x, 3))

        for i in range(500):
            x = random.random()
            self.assertEqual(float(format(x, '.0f')), round(x, 0))
            self.assertEqual(float(format(x, '.1f')), round(x, 1))
            self.assertEqual(float(format(x, '.2f')), round(x, 2))
            self.assertEqual(float(format(x, '.3f')), round(x, 3))

    def test_format_specials(self):
        # Test formatting of nans and infs.

        def test(fmt, value, expected):
            # Test with both % and format().
            self.assertEqual(fmt % value, expected, fmt)
            fmt = fmt[1:] # strip off the %
            self.assertEqual(format(value, fmt), expected, fmt)

        for fmt in ['%e', '%f', '%g', '%.0e', '%.6f', '%.20g',
                    '%#e', '%#f', '%#g', '%#.20e', '%#.15f', '%#.3g']:
            pfmt = '%+' + fmt[1:]
            sfmt = '% ' + fmt[1:]
            test(fmt, INF, 'inf')
            test(fmt, -INF, '-inf')
            test(fmt, NAN, 'nan')
            test(fmt, -NAN, 'nan')
            # When asking for a sign, it's always provided. nans are
            #  always positive.
            test(pfmt, INF, '+inf')
            test(pfmt, -INF, '-inf')
            test(pfmt, NAN, '+nan')
            test(pfmt, -NAN, '+nan')
            # When using ' ' for a sign code, only infs can be negative.
            #  Others have a space.
            test(sfmt, INF, ' inf')
            test(sfmt, -INF, '-inf')
            test(sfmt, NAN, ' nan')
            test(sfmt, -NAN, ' nan')

    def test_None_ndigits(self):
        for x in round(1.23), round(1.23, None), round(1.23, ndigits=None):
            self.assertEqual(x, 1)
            self.assertIsInstance(x, int)
        for x in round(1.78), round(1.78, None), round(1.78, ndigits=None):
            self.assertEqual(x, 2)
            self.assertIsInstance(x, int)


# Beginning with Python 2.6 float has cross platform compatible
# ways to create and represent inf and nan
class InfNanTest(unittest.TestCase):
    def test_inf_from_str(self):
        self.assertTrue(isinf(float("inf")))
        self.assertTrue(isinf(float("+inf")))
        self.assertTrue(isinf(float("-inf")))
        self.assertTrue(isinf(float("infinity")))
        self.assertTrue(isinf(float("+infinity")))
        self.assertTrue(isinf(float("-infinity")))

        self.assertEqual(repr(float("inf")), "inf")
        self.assertEqual(repr(float("+inf")), "inf")
        self.assertEqual(repr(float("-inf")), "-inf")
        self.assertEqual(repr(float("infinity")), "inf")
        self.assertEqual(repr(float("+infinity")), "inf")
        self.assertEqual(repr(float("-infinity")), "-inf")

        self.assertEqual(repr(float("INF")), "inf")
        self.assertEqual(repr(float("+Inf")), "inf")
        self.assertEqual(repr(float("-iNF")), "-inf")
        self.assertEqual(repr(float("Infinity")), "inf")
        self.assertEqual(repr(float("+iNfInItY")), "inf")
        self.assertEqual(repr(float("-INFINITY")), "-inf")

        self.assertEqual(str(float("inf")), "inf")
        self.assertEqual(str(float("+inf")), "inf")
        self.assertEqual(str(float("-inf")), "-inf")
        self.assertEqual(str(float("infinity")), "inf")
        self.assertEqual(str(float("+infinity")), "inf")
        self.assertEqual(str(float("-infinity")), "-inf")

        self.assertRaises(ValueError, float, "info")
        self.assertRaises(ValueError, float, "+info")
        self.assertRaises(ValueError, float, "-info")
        self.assertRaises(ValueError, float, "in")
        self.assertRaises(ValueError, float, "+in")
        self.assertRaises(ValueError, float, "-in")
        self.assertRaises(ValueError, float, "infinit")
        self.assertRaises(ValueError, float, "+Infin")
        self.assertRaises(ValueError, float, "-INFI")
        self.assertRaises(ValueError, float, "infinitys")

        self.assertRaises(ValueError, float, "++Inf")
        self.assertRaises(ValueError, float, "-+inf")
        self.assertRaises(ValueError, float, "+-infinity")
        self.assertRaises(ValueError, float, "--Infinity")

    def test_inf_as_str(self):
        self.assertEqual(repr(1e300 * 1e300), "inf")
        self.assertEqual(repr(-1e300 * 1e300), "-inf")

        self.assertEqual(str(1e300 * 1e300), "inf")
        self.assertEqual(str(-1e300 * 1e300), "-inf")

    def test_nan_from_str(self):
        self.assertTrue(isnan(float("nan")))
        self.assertTrue(isnan(float("+nan")))
        self.assertTrue(isnan(float("-nan")))

        self.assertEqual(repr(float("nan")), "nan")
        self.assertEqual(repr(float("+nan")), "nan")
        self.assertEqual(repr(float("-nan")), "nan")

        self.assertEqual(repr(float("NAN")), "nan")
        self.assertEqual(repr(float("+NAn")), "nan")
        self.assertEqual(repr(float("-NaN")), "nan")

        self.assertEqual(str(float("nan")), "nan")
        self.assertEqual(str(float("+nan")), "nan")
        self.assertEqual(str(float("-nan")), "nan")

        self.assertRaises(ValueError, float, "nana")
        self.assertRaises(ValueError, float, "+nana")
        self.assertRaises(ValueError, float, "-nana")
        self.assertRaises(ValueError, float, "na")
        self.assertRaises(ValueError, float, "+na")
        self.assertRaises(ValueError, float, "-na")

        self.assertRaises(ValueError, float, "++nan")
        self.assertRaises(ValueError, float, "-+NAN")
        self.assertRaises(ValueError, float, "+-NaN")
        self.assertRaises(ValueError, float, "--nAn")

    def test_nan_as_str(self):
        self.assertEqual(repr(1e300 * 1e300 * 0), "nan")
        self.assertEqual(repr(-1e300 * 1e300 * 0), "nan")

        self.assertEqual(str(1e300 * 1e300 * 0), "nan")
        self.assertEqual(str(-1e300 * 1e300 * 0), "nan")

    def test_inf_signs(self):
        self.assertEqual(copysign(1.0, float('inf')), 1.0)
        self.assertEqual(copysign(1.0, float('-inf')), -1.0)

    @unittest.skipUnless(getattr(sys, 'float_repr_style', '') == 'short',
                         "applies only when using short float repr style")
    def test_nan_signs(self):
        # When using the dtoa.c code, the sign of float('nan') should
        # be predictable.
        self.assertEqual(copysign(1.0, float('nan')), 1.0)
        self.assertEqual(copysign(1.0, float('-nan')), -1.0)


fromHex = float.fromhex
toHex = float.hex
class HexFloatTestCase(unittest.TestCase):
    MAX = fromHex('0x.fffffffffffff8p+1024')  # max normal
    MIN = fromHex('0x1p-1022')                # min normal
    TINY = fromHex('0x0.0000000000001p-1022') # min subnormal
    EPS = fromHex('0x0.0000000000001p0') # diff between 1.0 and next float up

    def identical(self, x, y):
        # check that floats x and y are identical, or that both
        # are NaNs
        if isnan(x) or isnan(y):
            if isnan(x) == isnan(y):
                return
        elif x == y and (x != 0.0 or copysign(1.0, x) == copysign(1.0, y)):
            return
        self.fail('%r not identical to %r' % (x, y))

    def test_ends(self):
        self.identical(self.MIN, ldexp(1.0, -1022))
        self.identical(self.TINY, ldexp(1.0, -1074))
        self.identical(self.EPS, ldexp(1.0, -52))
        self.identical(self.MAX, 2.*(ldexp(1.0, 1023) - ldexp(1.0, 970)))

    def test_invalid_inputs(self):
        invalid_inputs = [
            'infi',   # misspelt infinities and nans
            '-Infinit',
            '++inf',
            '-+Inf',
            '--nan',
            '+-NaN',
            'snan',
            'NaNs',
            'nna',
            'an',
            'nf',
            'nfinity',
            'inity',
            'iinity',
            '0xnan',
            '',
            ' ',
            'x1.0p0',
            '0xX1.0p0',
            '+ 0x1.0p0', # internal whitespace
            '- 0x1.0p0',
            '0 x1.0p0',
            '0x 1.0p0',
            '0x1 2.0p0',
            '+0x1 .0p0',
            '0x1. 0p0',
            '-0x1.0 1p0',
            '-0x1.0 p0',
            '+0x1.0p +0',
            '0x1.0p -0',
            '0x1.0p 0',
            '+0x1.0p+ 0',
            '-0x1.0p- 0',
            '++0x1.0p-0', # double signs
            '--0x1.0p0',
            '+-0x1.0p+0',
            '-+0x1.0p0',
            '0x1.0p++0',
            '+0x1.0p+-0',
            '-0x1.0p-+0',
            '0x1.0p--0',
            '0x1.0.p0',
            '0x.p0', # no hex digits before or after point
            '0x1,p0', # wrong decimal point character
            '0x1pa',
            '0x1p\uff10',  # fullwidth Unicode digits
            '\uff10x1p0',
            '0x\uff11p0',
            '0x1.\uff10p0',
            '0x1p0 \n 0x2p0',
            '0x1p0\0 0x1p0',  # embedded null byte is not end of string
            ]
        for x in invalid_inputs:
            try:
                result = fromHex(x)
            except ValueError:
                pass
            else:
                self.fail('Expected float.fromhex(%r) to raise ValueError; '
                          'got %r instead' % (x, result))


    def test_whitespace(self):
        value_pairs = [
            ('inf', INF),
            ('-Infinity', -INF),
            ('nan', NAN),
            ('1.0', 1.0),
            ('-0x.2', -0.125),
            ('-0.0', -0.0)
            ]
        whitespace = [
            '',
            ' ',
            '\t',
            '\n',
            '\n \t',
            '\f',
            '\v',
            '\r'
            ]
        for inp, expected in value_pairs:
            for lead in whitespace:
                for trail in whitespace:
                    got = fromHex(lead + inp + trail)
                    self.identical(got, expected)


    def test_from_hex(self):
        MIN = self.MIN;
        MAX = self.MAX;
        TINY = self.TINY;
        EPS = self.EPS;

        # two spellings of infinity, with optional signs; case-insensitive
        self.identical(fromHex('inf'), INF)
        self.identical(fromHex('+Inf'), INF)
        self.identical(fromHex('-INF'), -INF)
        self.identical(fromHex('iNf'), INF)
        self.identical(fromHex('Infinity'), INF)
        self.identical(fromHex('+INFINITY'), INF)
        self.identical(fromHex('-infinity'), -INF)
        self.identical(fromHex('-iNFiNitY'), -INF)

        # nans with optional sign; case insensitive
        self.identical(fromHex('nan'), NAN)
        self.identical(fromHex('+NaN'), NAN)
        self.identical(fromHex('-NaN'), NAN)
        self.identical(fromHex('-nAN'), NAN)

        # variations in input format
        self.identical(fromHex('1'), 1.0)
        self.identical(fromHex('+1'), 1.0)
        self.identical(fromHex('1.'), 1.0)
        self.identical(fromHex('1.0'), 1.0)
        self.identical(fromHex('1.0p0'), 1.0)
        self.identical(fromHex('01'), 1.0)
        self.identical(fromHex('01.'), 1.0)
        self.identical(fromHex('0x1'), 1.0)
        self.identical(fromHex('0x1.'), 1.0)
        self.identical(fromHex('0x1.0'), 1.0)
        self.identical(fromHex('+0x1.0'), 1.0)
        self.identical(fromHex('0x1p0'), 1.0)
        self.identical(fromHex('0X1p0'), 1.0)
        self.identical(fromHex('0X1P0'), 1.0)
        self.identical(fromHex('0x1P0'), 1.0)
        self.identical(fromHex('0x1.p0'), 1.0)
        self.identical(fromHex('0x1.0p0'), 1.0)
        self.identical(fromHex('0x.1p4'), 1.0)
        self.identical(fromHex('0x.1p04'), 1.0)
        self.identical(fromHex('0x.1p004'), 1.0)
        self.identical(fromHex('0x1p+0'), 1.0)
        self.identical(fromHex('0x1P-0'), 1.0)
        self.identical(fromHex('+0x1p0'), 1.0)
        self.identical(fromHex('0x01p0'), 1.0)
        self.identical(fromHex('0x1p00'), 1.0)
        self.identical(fromHex(' 0x1p0 '), 1.0)
        self.identical(fromHex('\n 0x1p0'), 1.0)
        self.identical(fromHex('0x1p0 \t'), 1.0)
        self.identical(fromHex('0xap0'), 10.0)
        self.identical(fromHex('0xAp0'), 10.0)
        self.identical(fromHex('0xaP0'), 10.0)
        self.identical(fromHex('0xAP0'), 10.0)
        self.identical(fromHex('0xbep0'), 190.0)
        self.identical(fromHex('0xBep0'), 190.0)
        self.identical(fromHex('0xbEp0'), 190.0)
        self.identical(fromHex('0XBE0P-4'), 190.0)
        self.identical(fromHex('0xBEp0'), 190.0)
        self.identical(fromHex('0xB.Ep4'), 190.0)
        self.identical(fromHex('0x.BEp8'), 190.0)
        self.identical(fromHex('0x.0BEp12'), 190.0)

        # moving the point around
        pi = fromHex('0x1.921fb54442d18p1')
        self.identical(fromHex('0x.006487ed5110b46p11'), pi)
        self.identical(fromHex('0x.00c90fdaa22168cp10'), pi)
        self.identical(fromHex('0x.01921fb54442d18p9'), pi)
        self.identical(fromHex('0x.03243f6a8885a3p8'), pi)
        self.identical(fromHex('0x.06487ed5110b46p7'), pi)
        self.identical(fromHex('0x.0c90fdaa22168cp6'), pi)
        self.identical(fromHex('0x.1921fb54442d18p5'), pi)
        self.identical(fromHex('0x.3243f6a8885a3p4'), pi)
        self.identical(fromHex('0x.6487ed5110b46p3'), pi)
        self.identical(fromHex('0x.c90fdaa22168cp2'), pi)
        self.identical(fromHex('0x1.921fb54442d18p1'), pi)
        self.identical(fromHex('0x3.243f6a8885a3p0'), pi)
        self.identical(fromHex('0x6.487ed5110b46p-1'), pi)
        self.identical(fromHex('0xc.90fdaa22168cp-2'), pi)
        self.identical(fromHex('0x19.21fb54442d18p-3'), pi)
        self.identical(fromHex('0x32.43f6a8885a3p-4'), pi)
        self.identical(fromHex('0x64.87ed5110b46p-5'), pi)
        self.identical(fromHex('0xc9.0fdaa22168cp-6'), pi)
        self.identical(fromHex('0x192.1fb54442d18p-7'), pi)
        self.identical(fromHex('0x324.3f6a8885a3p-8'), pi)
        self.identical(fromHex('0x648.7ed5110b46p-9'), pi)
        self.identical(fromHex('0xc90.fdaa22168cp-10'), pi)
        self.identical(fromHex('0x1921.fb54442d18p-11'), pi)
        # ...
        self.identical(fromHex('0x1921fb54442d1.8p-47'), pi)
        self.identical(fromHex('0x3243f6a8885a3p-48'), pi)
        self.identical(fromHex('0x6487ed5110b46p-49'), pi)
        self.identical(fromHex('0xc90fdaa22168cp-50'), pi)
        self.identical(fromHex('0x1921fb54442d18p-51'), pi)
        self.identical(fromHex('0x3243f6a8885a30p-52'), pi)
        self.identical(fromHex('0x6487ed5110b460p-53'), pi)
        self.identical(fromHex('0xc90fdaa22168c0p-54'), pi)
        self.identical(fromHex('0x1921fb54442d180p-55'), pi)


        # results that should overflow...
        self.assertRaises(OverflowError, fromHex, '-0x1p1024')
        self.assertRaises(OverflowError, fromHex, '0x1p+1025')
        self.assertRaises(OverflowError, fromHex, '+0X1p1030')
        self.assertRaises(OverflowError, fromHex, '-0x1p+1100')
        self.assertRaises(OverflowError, fromHex, '0X1p123456789123456789')
        self.assertRaises(OverflowError, fromHex, '+0X.8p+1025')
        self.assertRaises(OverflowError, fromHex, '+0x0.8p1025')
        self.assertRaises(OverflowError, fromHex, '-0x0.4p1026')
        self.assertRaises(OverflowError, fromHex, '0X2p+1023')
        self.assertRaises(OverflowError, fromHex, '0x2.p1023')
        self.assertRaises(OverflowError, fromHex, '-0x2.0p+1023')
        self.assertRaises(OverflowError, fromHex, '+0X4p+1022')
        self.assertRaises(OverflowError, fromHex, '0x1.ffffffffffffffp+1023')
        self.assertRaises(OverflowError, fromHex, '-0X1.fffffffffffff9p1023')
        self.assertRaises(OverflowError, fromHex, '0X1.fffffffffffff8p1023')
        self.assertRaises(OverflowError, fromHex, '+0x3.fffffffffffffp1022')
        self.assertRaises(OverflowError, fromHex, '0x3fffffffffffffp+970')
        self.assertRaises(OverflowError, fromHex, '0x10000000000000000p960')
        self.assertRaises(OverflowError, fromHex, '-0Xffffffffffffffffp960')

        # ...and those that round to +-max float
        self.identical(fromHex('+0x1.fffffffffffffp+1023'), MAX)
        self.identical(fromHex('-0X1.fffffffffffff7p1023'), -MAX)
        self.identical(fromHex('0X1.fffffffffffff7fffffffffffffp1023'), MAX)

        # zeros
        self.identical(fromHex('0x0p0'), 0.0)
        self.identical(fromHex('0x0p1000'), 0.0)
        self.identical(fromHex('-0x0p1023'), -0.0)
        self.identical(fromHex('0X0p1024'), 0.0)
        self.identical(fromHex('-0x0p1025'), -0.0)
        self.identical(fromHex('0X0p2000'), 0.0)
        self.identical(fromHex('0x0p123456789123456789'), 0.0)
        self.identical(fromHex('-0X0p-0'), -0.0)
        self.identical(fromHex('-0X0p-1000'), -0.0)
        self.identical(fromHex('0x0p-1023'), 0.0)
        self.identical(fromHex('-0X0p-1024'), -0.0)
        self.identical(fromHex('-0x0p-1025'), -0.0)
        self.identical(fromHex('-0x0p-1072'), -0.0)
        self.identical(fromHex('0X0p-1073'), 0.0)
        self.identical(fromHex('-0x0p-1074'), -0.0)
        self.identical(fromHex('0x0p-1075'), 0.0)
        self.identical(fromHex('0X0p-1076'), 0.0)
        self.identical(fromHex('-0X0p-2000'), -0.0)
        self.identical(fromHex('-0x0p-123456789123456789'), -0.0)

        # values that should underflow to 0
        self.identical(fromHex('0X1p-1075'), 0.0)
        self.identical(fromHex('-0X1p-1075'), -0.0)
        self.identical(fromHex('-0x1p-123456789123456789'), -0.0)
        self.identical(fromHex('0x1.00000000000000001p-1075'), TINY)
        self.identical(fromHex('-0x1.1p-1075'), -TINY)
        self.identical(fromHex('0x1.fffffffffffffffffp-1075'), TINY)

        # check round-half-even is working correctly near 0 ...
        self.identical(fromHex('0x1p-1076'), 0.0)
        self.identical(fromHex('0X2p-1076'), 0.0)
        self.identical(fromHex('0X3p-1076'), TINY)
        self.identical(fromHex('0x4p-1076'), TINY)
        self.identical(fromHex('0X5p-1076'), TINY)
        self.identical(fromHex('0X6p-1076'), 2*TINY)
        self.identical(fromHex('0x7p-1076'), 2*TINY)
        self.identical(fromHex('0X8p-1076'), 2*TINY)
        self.identical(fromHex('0X9p-1076'), 2*TINY)
        self.identical(fromHex('0xap-1076'), 2*TINY)
        self.identical(fromHex('0Xbp-1076'), 3*TINY)
        self.identical(fromHex('0xcp-1076'), 3*TINY)
        self.identical(fromHex('0Xdp-1076'), 3*TINY)
        self.identical(fromHex('0Xep-1076'), 4*TINY)
        self.identical(fromHex('0xfp-1076'), 4*TINY)
        self.identical(fromHex('0x10p-1076'), 4*TINY)
        self.identical(fromHex('-0x1p-1076'), -0.0)
        self.identical(fromHex('-0X2p-1076'), -0.0)
        self.identical(fromHex('-0x3p-1076'), -TINY)
        self.identical(fromHex('-0X4p-1076'), -TINY)
        self.identical(fromHex('-0x5p-1076'), -TINY)
        self.identical(fromHex('-0x6p-1076'), -2*TINY)
        self.identical(fromHex('-0X7p-1076'), -2*TINY)
        self.identical(fromHex('-0X8p-1076'), -2*TINY)
        self.identical(fromHex('-0X9p-1076'), -2*TINY)
        self.identical(fromHex('-0Xap-1076'), -2*TINY)
        self.identical(fromHex('-0xbp-1076'), -3*TINY)
        self.identical(fromHex('-0xcp-1076'), -3*TINY)
        self.identical(fromHex('-0Xdp-1076'), -3*TINY)
        self.identical(fromHex('-0xep-1076'), -4*TINY)
        self.identical(fromHex('-0Xfp-1076'), -4*TINY)
        self.identical(fromHex('-0X10p-1076'), -4*TINY)

        # ... and near MIN ...
        self.identical(fromHex('0x0.ffffffffffffd6p-1022'), MIN-3*TINY)
        self.identical(fromHex('0x0.ffffffffffffd8p-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffdap-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffdcp-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffdep-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffe0p-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffe2p-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffe4p-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffe6p-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffe8p-1022'), MIN-2*TINY)
        self.identical(fromHex('0x0.ffffffffffffeap-1022'), MIN-TINY)
        self.identical(fromHex('0x0.ffffffffffffecp-1022'), MIN-TINY)
        self.identical(fromHex('0x0.ffffffffffffeep-1022'), MIN-TINY)
        self.identical(fromHex('0x0.fffffffffffff0p-1022'), MIN-TINY)
        self.identical(fromHex('0x0.fffffffffffff2p-1022'), MIN-TINY)
        self.identical(fromHex('0x0.fffffffffffff4p-1022'), MIN-TINY)
        self.identical(fromHex('0x0.fffffffffffff6p-1022'), MIN-TINY)
        self.identical(fromHex('0x0.fffffffffffff8p-1022'), MIN)
        self.identical(fromHex('0x0.fffffffffffffap-1022'), MIN)
        self.identical(fromHex('0x0.fffffffffffffcp-1022'), MIN)
        self.identical(fromHex('0x0.fffffffffffffep-1022'), MIN)
        self.identical(fromHex('0x1.00000000000000p-1022'), MIN)
        self.identical(fromHex('0x1.00000000000002p-1022'), MIN)
        self.identical(fromHex('0x1.00000000000004p-1022'), MIN)
        self.identical(fromHex('0x1.00000000000006p-1022'), MIN)
        self.identical(fromHex('0x1.00000000000008p-1022'), MIN)
        self.identical(fromHex('0x1.0000000000000ap-1022'), MIN+TINY)
        self.identical(fromHex('0x1.0000000000000cp-1022'), MIN+TINY)
        self.identical(fromHex('0x1.0000000000000ep-1022'), MIN+TINY)
        self.identical(fromHex('0x1.00000000000010p-1022'), MIN+TINY)
        self.identical(fromHex('0x1.00000000000012p-1022'), MIN+TINY)
        self.identical(fromHex('0x1.00000000000014p-1022'), MIN+TINY)
        self.identical(fromHex('0x1.00000000000016p-1022'), MIN+TINY)
        self.identical(fromHex('0x1.00000000000018p-1022'), MIN+2*TINY)

        # ... and near 1.0.
        self.identical(fromHex('0x0.fffffffffffff0p0'), 1.0-EPS)
        self.identical(fromHex('0x0.fffffffffffff1p0'), 1.0-EPS)
        self.identical(fromHex('0X0.fffffffffffff2p0'), 1.0-EPS)
        self.identical(fromHex('0x0.fffffffffffff3p0'), 1.0-EPS)
        self.identical(fromHex('0X0.fffffffffffff4p0'), 1.0-EPS)
        self.identical(fromHex('0X0.fffffffffffff5p0'), 1.0-EPS/2)
        self.identical(fromHex('0X0.fffffffffffff6p0'), 1.0-EPS/2)
        self.identical(fromHex('0x0.fffffffffffff7p0'), 1.0-EPS/2)
        self.identical(fromHex('0x0.fffffffffffff8p0'), 1.0-EPS/2)
        self.identical(fromHex('0X0.fffffffffffff9p0'), 1.0-EPS/2)
        self.identical(fromHex('0X0.fffffffffffffap0'), 1.0-EPS/2)
        self.identical(fromHex('0x0.fffffffffffffbp0'), 1.0-EPS/2)
        self.identical(fromHex('0X0.fffffffffffffcp0'), 1.0)
        self.identical(fromHex('0x0.fffffffffffffdp0'), 1.0)
        self.identical(fromHex('0X0.fffffffffffffep0'), 1.0)
        self.identical(fromHex('0x0.ffffffffffffffp0'), 1.0)
        self.identical(fromHex('0X1.00000000000000p0'), 1.0)
        self.identical(fromHex('0X1.00000000000001p0'), 1.0)
        self.identical(fromHex('0x1.00000000000002p0'), 1.0)
        self.identical(fromHex('0X1.00000000000003p0'), 1.0)
        self.identical(fromHex('0x1.00000000000004p0'), 1.0)
        self.identical(fromHex('0X1.00000000000005p0'), 1.0)
        self.identical(fromHex('0X1.00000000000006p0'), 1.0)
        self.identical(fromHex('0X1.00000000000007p0'), 1.0)
        self.identical(fromHex('0x1.00000000000007ffffffffffffffffffffp0'),
                       1.0)
        self.identical(fromHex('0x1.00000000000008p0'), 1.0)
        self.identical(fromHex('0x1.00000000000008000000000000000001p0'),
                       1+EPS)
        self.identical(fromHex('0X1.00000000000009p0'), 1.0+EPS)
        self.identical(fromHex('0x1.0000000000000ap0'), 1.0+EPS)
        self.identical(fromHex('0x1.0000000000000bp0'), 1.0+EPS)
        self.identical(fromHex('0X1.0000000000000cp0'), 1.0+EPS)
        self.identical(fromHex('0x1.0000000000000dp0'), 1.0+EPS)
        self.identical(fromHex('0x1.0000000000000ep0'), 1.0+EPS)
        self.identical(fromHex('0X1.0000000000000fp0'), 1.0+EPS)
        self.identical(fromHex('0x1.00000000000010p0'), 1.0+EPS)
        self.identical(fromHex('0X1.00000000000011p0'), 1.0+EPS)
        self.identical(fromHex('0x1.00000000000012p0'), 1.0+EPS)
        self.identical(fromHex('0X1.00000000000013p0'), 1.0+EPS)
        self.identical(fromHex('0X1.00000000000014p0'), 1.0+EPS)
        self.identical(fromHex('0x1.00000000000015p0'), 1.0+EPS)
        self.identical(fromHex('0x1.00000000000016p0'), 1.0+EPS)
        self.identical(fromHex('0X1.00000000000017p0'), 1.0+EPS)
        self.identical(fromHex('0x1.00000000000017ffffffffffffffffffffp0'),
                       1.0+EPS)
        self.identical(fromHex('0x1.00000000000018p0'), 1.0+2*EPS)
        self.identical(fromHex('0X1.00000000000018000000000000000001p0'),
                       1.0+2*EPS)
        self.identical(fromHex('0x1.00000000000019p0'), 1.0+2*EPS)
        self.identical(fromHex('0X1.0000000000001ap0'), 1.0+2*EPS)
        self.identical(fromHex('0X1.0000000000001bp0'), 1.0+2*EPS)
        self.identical(fromHex('0x1.0000000000001cp0'), 1.0+2*EPS)
        self.identical(fromHex('0x1.0000000000001dp0'), 1.0+2*EPS)
        self.identical(fromHex('0x1.0000000000001ep0'), 1.0+2*EPS)
        self.identical(fromHex('0X1.0000000000001fp0'), 1.0+2*EPS)
        self.identical(fromHex('0x1.00000000000020p0'), 1.0+2*EPS)

    def test_roundtrip(self):
        def roundtrip(x):
            return fromHex(toHex(x))

        for x in [NAN, INF, self.MAX, self.MIN, self.MIN-self.TINY, self.TINY, 0.0]:
            self.identical(x, roundtrip(x))
            self.identical(-x, roundtrip(-x))

        # fromHex(toHex(x)) should exactly recover x, for any non-NaN float x.
        import random
        for i in range(10000):
            e = random.randrange(-1200, 1200)
            m = random.random()
            s = random.choice([1.0, -1.0])
            try:
                x = s*ldexp(m, e)
            except OverflowError:
                pass
            else:
                self.identical(x, fromHex(toHex(x)))

    def test_subclass(self):
        class F(float):
            def __new__(cls, value):
                return float.__new__(cls, value + 1)

        f = F.fromhex((1.5).hex())
        self.assertIs(type(f), F)
        self.assertEqual(f, 2.5)

        class F2(float):
            def __init__(self, value):
                self.foo = 'bar'

        f = F2.fromhex((1.5).hex())
        self.assertIs(type(f), F2)
        self.assertEqual(f, 1.5)
        self.assertEqual(getattr(f, 'foo', 'none'), 'bar')


if __name__ == '__main__':
    unittest.main()
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