import math
import sys
import unittest
import warnings
from test.test_capi.test_getargs import (Float, FloatSubclass, FloatSubclass2,
BadIndex2, BadFloat2, Index, BadIndex,
BadFloat)
from test.support import import_helper
_testcapi = import_helper.import_module('_testcapi')
_testlimitedcapi = import_helper.import_module('_testlimitedcapi')
NULL = None
# For PyFloat_Pack/Unpack*
BIG_ENDIAN = 0
LITTLE_ENDIAN = 1
EPSILON = {
2: 2.0 ** -11, # binary16
4: 2.0 ** -24, # binary32
8: 2.0 ** -53, # binary64
}
HAVE_IEEE_754 = float.__getformat__("double").startswith("IEEE")
INF = float("inf")
NAN = float("nan")
class CAPIFloatTest(unittest.TestCase):
def test_check(self):
# Test PyFloat_Check()
check = _testlimitedcapi.float_check
self.assertTrue(check(4.25))
self.assertTrue(check(FloatSubclass(4.25)))
self.assertFalse(check(Float()))
self.assertFalse(check(3))
self.assertFalse(check(object()))
# CRASHES check(NULL)
def test_checkexact(self):
# Test PyFloat_CheckExact()
checkexact = _testlimitedcapi.float_checkexact
self.assertTrue(checkexact(4.25))
self.assertFalse(checkexact(FloatSubclass(4.25)))
self.assertFalse(checkexact(Float()))
self.assertFalse(checkexact(3))
self.assertFalse(checkexact(object()))
# CRASHES checkexact(NULL)
def test_fromstring(self):
# Test PyFloat_FromString()
fromstring = _testlimitedcapi.float_fromstring
self.assertEqual(fromstring("4.25"), 4.25)
self.assertEqual(fromstring(b"4.25"), 4.25)
self.assertRaises(ValueError, fromstring, "4.25\0")
self.assertRaises(ValueError, fromstring, b"4.25\0")
self.assertEqual(fromstring(bytearray(b"4.25")), 4.25)
self.assertEqual(fromstring(memoryview(b"4.25")), 4.25)
self.assertEqual(fromstring(memoryview(b"4.255")[:-1]), 4.25)
self.assertRaises(TypeError, fromstring, memoryview(b"4.25")[::2])
self.assertRaises(TypeError, fromstring, 4.25)
# CRASHES fromstring(NULL)
def test_fromdouble(self):
# Test PyFloat_FromDouble()
fromdouble = _testlimitedcapi.float_fromdouble
self.assertEqual(fromdouble(4.25), 4.25)
def test_asdouble(self):
# Test PyFloat_AsDouble()
asdouble = _testlimitedcapi.float_asdouble
class BadFloat3:
def __float__(self):
raise RuntimeError
self.assertEqual(asdouble(4.25), 4.25)
self.assertEqual(asdouble(-1.0), -1.0)
self.assertEqual(asdouble(42), 42.0)
self.assertEqual(asdouble(-1), -1.0)
self.assertEqual(asdouble(2**1000), float(2**1000))
self.assertEqual(asdouble(FloatSubclass(4.25)), 4.25)
self.assertEqual(asdouble(FloatSubclass2(4.25)), 4.25)
self.assertEqual(asdouble(Index()), 99.)
self.assertRaises(TypeError, asdouble, BadIndex())
self.assertRaises(TypeError, asdouble, BadFloat())
self.assertRaises(RuntimeError, asdouble, BadFloat3())
with self.assertWarns(DeprecationWarning):
self.assertEqual(asdouble(BadIndex2()), 1.)
with self.assertWarns(DeprecationWarning):
self.assertEqual(asdouble(BadFloat2()), 4.25)
with warnings.catch_warnings():
warnings.simplefilter("error", DeprecationWarning)
self.assertRaises(DeprecationWarning, asdouble, BadFloat2())
self.assertRaises(TypeError, asdouble, object())
self.assertRaises(TypeError, asdouble, NULL)
def test_getinfo(self):
# Test PyFloat_GetInfo()
getinfo = _testlimitedcapi.float_getinfo
self.assertEqual(getinfo(), sys.float_info)
def test_getmax(self):
# Test PyFloat_GetMax()
getmax = _testlimitedcapi.float_getmax
self.assertEqual(getmax(), sys.float_info.max)
def test_getmin(self):
# Test PyFloat_GetMax()
getmin = _testlimitedcapi.float_getmin
self.assertEqual(getmin(), sys.float_info.min)
def test_pack(self):
# Test PyFloat_Pack2(), PyFloat_Pack4() and PyFloat_Pack8()
pack = _testcapi.float_pack
self.assertEqual(pack(2, 1.5, BIG_ENDIAN), b'>\x00')
self.assertEqual(pack(4, 1.5, BIG_ENDIAN), b'?\xc0\x00\x00')
self.assertEqual(pack(8, 1.5, BIG_ENDIAN),
b'?\xf8\x00\x00\x00\x00\x00\x00')
self.assertEqual(pack(2, 1.5, LITTLE_ENDIAN), b'\x00>')
self.assertEqual(pack(4, 1.5, LITTLE_ENDIAN), b'\x00\x00\xc0?')
self.assertEqual(pack(8, 1.5, LITTLE_ENDIAN),
b'\x00\x00\x00\x00\x00\x00\xf8?')
def test_unpack(self):
# Test PyFloat_Unpack2(), PyFloat_Unpack4() and PyFloat_Unpack8()
unpack = _testcapi.float_unpack
self.assertEqual(unpack(b'>\x00', BIG_ENDIAN), 1.5)
self.assertEqual(unpack(b'?\xc0\x00\x00', BIG_ENDIAN), 1.5)
self.assertEqual(unpack(b'?\xf8\x00\x00\x00\x00\x00\x00', BIG_ENDIAN),
1.5)
self.assertEqual(unpack(b'\x00>', LITTLE_ENDIAN), 1.5)
self.assertEqual(unpack(b'\x00\x00\xc0?', LITTLE_ENDIAN), 1.5)
self.assertEqual(unpack(b'\x00\x00\x00\x00\x00\x00\xf8?', LITTLE_ENDIAN),
1.5)
def test_pack_unpack_roundtrip(self):
pack = _testcapi.float_pack
unpack = _testcapi.float_unpack
large = 2.0 ** 100
values = [1.0, 1.5, large, 1.0/7, math.pi]
if HAVE_IEEE_754:
values.extend((INF, NAN))
for value in values:
for size in (2, 4, 8,):
if size == 2 and value == large:
# too large for 16-bit float
continue
rel_tol = EPSILON[size]
for endian in (BIG_ENDIAN, LITTLE_ENDIAN):
with self.subTest(value=value, size=size, endian=endian):
data = pack(size, value, endian)
value2 = unpack(data, endian)
if math.isnan(value):
self.assertTrue(math.isnan(value2), (value, value2))
elif size < 8:
self.assertTrue(math.isclose(value2, value, rel_tol=rel_tol),
(value, value2))
else:
self.assertEqual(value2, value)
if __name__ == "__main__":
unittest.main()