cpython/Lib/test/test_float.py

1346 lines
59 KiB
Python

import fractions
import math
import operator
import os
import random
import sys
import struct
import time
import unittest
from test import support
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 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(UnicodeEncodeError, 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)
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):
testlist = ('\xbd', '123\xbd', ' 123 456 ')
for s in testlist:
try:
float(s)
except ValueError as e:
self.assertIn(s.strip(), e.args[0])
else:
self.fail("Expected int(%r) to raise a ValueError", s)
@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.assertAlmostEqual(float(Foo1()), 42.)
self.assertAlmostEqual(float(Foo2()), 42.)
self.assertAlmostEqual(float(Foo3(21)), 42.)
self.assertRaises(TypeError, float, Foo4(42))
self.assertAlmostEqual(float(FooStr('8')), 9.)
class Foo5:
def __float__(self):
return ""
self.assertRaises(TypeError, time.sleep, Foo5())
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)
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')
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)))
if __name__ == '__main__':
unittest.main()