import math import random import platform 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") def make_nan(size, sign, quiet, payload=None): if size == 8: payload_mask = 0x7ffffffffffff i = (sign << 63) + (0x7ff << 52) + (quiet << 51) elif size == 4: payload_mask = 0x3fffff i = (sign << 31) + (0xff << 23) + (quiet << 22) elif size == 2: payload_mask = 0x1ff i = (sign << 15) + (0x1f << 10) + (quiet << 9) else: raise ValueError("size must be either 2, 4, or 8") if payload is None: payload = random.randint(not quiet, payload_mask) return i + payload 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) @unittest.skipUnless(HAVE_IEEE_754, "requires IEEE 754") def test_pack_unpack_roundtrip_for_nans(self): pack = _testcapi.float_pack unpack = _testcapi.float_unpack for _ in range(10): for size in (2, 4, 8): sign = random.randint(0, 1) if sys.maxsize != 2147483647: # not it 32-bit mode signaling = random.randint(0, 1) else: # Skip sNaN's on x86 (32-bit). The problem is that sNaN # doubles become qNaN doubles just by the C calling # convention, there is no way to preserve sNaN doubles # between C function calls with the current # PyFloat_Pack/Unpack*() API. See also gh-130317 and # e.g. https://developercommunity.visualstudio.com/t/155064 signaling = 0 if platform.machine().startswith('parisc'): # HP PA RISC uses 0 for quiet, see: # https://en.wikipedia.org/wiki/NaN#Encoding signaling = 1 i = make_nan(size, sign, not signaling) data = bytes.fromhex(f'{i:x}') for endian in (BIG_ENDIAN, LITTLE_ENDIAN): with self.subTest(data=data, size=size, endian=endian): data1 = data if endian == BIG_ENDIAN else data[::-1] value = unpack(data1, endian) data2 = pack(size, value, endian) self.assertTrue(math.isnan(value)) self.assertEqual(data1, data2) @unittest.skipUnless(HAVE_IEEE_754, "requires IEEE 754") @unittest.skipUnless(sys.maxsize != 2147483647, "requires 64-bit mode") def test_pack_unpack_nans_for_different_formats(self): pack = _testcapi.float_pack unpack = _testcapi.float_unpack for endian in (BIG_ENDIAN, LITTLE_ENDIAN): with self.subTest(endian=endian): byteorder = "big" if endian == BIG_ENDIAN else "little" # Convert sNaN to qNaN, if payload got truncated data = make_nan(8, 0, False, 0x80001).to_bytes(8, byteorder) snan_low = unpack(data, endian) qnan4 = make_nan(4, 0, True, 0).to_bytes(4, byteorder) qnan2 = make_nan(2, 0, True, 0).to_bytes(2, byteorder) self.assertEqual(pack(4, snan_low, endian), qnan4) self.assertEqual(pack(2, snan_low, endian), qnan2) # Preserve NaN type, if payload not truncated data = make_nan(8, 0, False, 0x80000000001).to_bytes(8, byteorder) snan_high = unpack(data, endian) snan4 = make_nan(4, 0, False, 16384).to_bytes(4, byteorder) snan2 = make_nan(2, 0, False, 2).to_bytes(2, byteorder) self.assertEqual(pack(4, snan_high, endian), snan4) self.assertEqual(pack(2, snan_high, endian), snan2) if __name__ == "__main__": unittest.main()