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212 lines
8 KiB
Python
212 lines
8 KiB
Python
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import unittest, struct
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import os
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from test import test_support
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def isinf(x):
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return x * 0.5 == x
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def isnan(x):
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return x != x
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class FormatFunctionsTestCase(unittest.TestCase):
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def setUp(self):
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self.save_formats = {'double':float.__getformat__('double'),
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'float':float.__getformat__('float')}
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def tearDown(self):
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float.__setformat__('double', self.save_formats['double'])
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float.__setformat__('float', self.save_formats['float'])
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def test_getformat(self):
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self.assert_(float.__getformat__('double') in
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['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
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self.assert_(float.__getformat__('float') in
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['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
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self.assertRaises(ValueError, float.__getformat__, 'chicken')
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self.assertRaises(TypeError, float.__getformat__, 1)
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def test_setformat(self):
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for t in 'double', 'float':
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float.__setformat__(t, 'unknown')
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if self.save_formats[t] == 'IEEE, big-endian':
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, little-endian')
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elif self.save_formats[t] == 'IEEE, little-endian':
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, big-endian')
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else:
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, big-endian')
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, little-endian')
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self.assertRaises(ValueError, float.__setformat__,
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t, 'chicken')
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self.assertRaises(ValueError, float.__setformat__,
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'chicken', 'unknown')
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BE_DOUBLE_INF = '\x7f\xf0\x00\x00\x00\x00\x00\x00'
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LE_DOUBLE_INF = ''.join(reversed(BE_DOUBLE_INF))
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BE_DOUBLE_NAN = '\x7f\xf8\x00\x00\x00\x00\x00\x00'
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LE_DOUBLE_NAN = ''.join(reversed(BE_DOUBLE_NAN))
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BE_FLOAT_INF = '\x7f\x80\x00\x00'
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LE_FLOAT_INF = ''.join(reversed(BE_FLOAT_INF))
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BE_FLOAT_NAN = '\x7f\xc0\x00\x00'
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LE_FLOAT_NAN = ''.join(reversed(BE_FLOAT_NAN))
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# on non-IEEE platforms, attempting to unpack a bit pattern
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# representing an infinity or a NaN should raise an exception.
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class UnknownFormatTestCase(unittest.TestCase):
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def setUp(self):
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self.save_formats = {'double':float.__getformat__('double'),
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'float':float.__getformat__('float')}
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float.__setformat__('double', 'unknown')
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float.__setformat__('float', 'unknown')
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def tearDown(self):
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float.__setformat__('double', self.save_formats['double'])
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float.__setformat__('float', self.save_formats['float'])
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def test_double_specials_dont_unpack(self):
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for fmt, data in [('>d', BE_DOUBLE_INF),
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('>d', BE_DOUBLE_NAN),
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('<d', LE_DOUBLE_INF),
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('<d', LE_DOUBLE_NAN)]:
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self.assertRaises(ValueError, struct.unpack, fmt, data)
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def test_float_specials_dont_unpack(self):
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for fmt, data in [('>f', BE_FLOAT_INF),
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('>f', BE_FLOAT_NAN),
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('<f', LE_FLOAT_INF),
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('<f', LE_FLOAT_NAN)]:
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self.assertRaises(ValueError, struct.unpack, fmt, data)
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# on an IEEE platform, all we guarantee is that bit patterns
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# representing infinities or NaNs do not raise an exception; all else
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# is accident (today).
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# let's also try to guarantee that -0.0 and 0.0 don't get confused.
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class IEEEFormatTestCase(unittest.TestCase):
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if float.__getformat__("double").startswith("IEEE"):
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def test_double_specials_do_unpack(self):
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for fmt, data in [('>d', BE_DOUBLE_INF),
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('>d', BE_DOUBLE_NAN),
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('<d', LE_DOUBLE_INF),
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('<d', LE_DOUBLE_NAN)]:
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struct.unpack(fmt, data)
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if float.__getformat__("float").startswith("IEEE"):
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def test_float_specials_do_unpack(self):
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for fmt, data in [('>f', BE_FLOAT_INF),
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('>f', BE_FLOAT_NAN),
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('<f', LE_FLOAT_INF),
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('<f', LE_FLOAT_NAN)]:
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struct.unpack(fmt, data)
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if float.__getformat__("double").startswith("IEEE"):
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def test_negative_zero(self):
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import math
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def pos_pos():
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return 0.0, math.atan2(0.0, -1)
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def pos_neg():
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return 0.0, math.atan2(-0.0, -1)
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def neg_pos():
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return -0.0, math.atan2(0.0, -1)
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def neg_neg():
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return -0.0, math.atan2(-0.0, -1)
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self.assertEquals(pos_pos(), neg_pos())
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self.assertEquals(pos_neg(), neg_neg())
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class ReprTestCase(unittest.TestCase):
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def test_repr(self):
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floats_file = open(os.path.join(os.path.split(__file__)[0],
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'floating_points.txt'))
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for line in floats_file:
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line = line.strip()
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if not line or line.startswith('#'):
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continue
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v = eval(line)
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self.assertEqual(v, eval(repr(v)))
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floats_file.close()
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# Beginning with Python 2.6 float has cross platform compatible
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# ways to create and representate inf and nan
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class InfNanTest(unittest.TestCase):
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def test_inf_from_str(self):
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self.assert_(isinf(float("inf")))
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self.assert_(isinf(float("+inf")))
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self.assert_(isinf(float("-inf")))
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self.assertEqual(repr(float("inf")), "inf")
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self.assertEqual(repr(float("+inf")), "inf")
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self.assertEqual(repr(float("-inf")), "-inf")
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self.assertEqual(repr(float("INF")), "inf")
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self.assertEqual(repr(float("+Inf")), "inf")
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self.assertEqual(repr(float("-iNF")), "-inf")
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self.assertEqual(str(float("inf")), "inf")
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self.assertEqual(str(float("+inf")), "inf")
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self.assertEqual(str(float("-inf")), "-inf")
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self.assertRaises(ValueError, float, "info")
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self.assertRaises(ValueError, float, "+info")
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self.assertRaises(ValueError, float, "-info")
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self.assertRaises(ValueError, float, "in")
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self.assertRaises(ValueError, float, "+in")
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self.assertRaises(ValueError, float, "-in")
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def test_inf_as_str(self):
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self.assertEqual(repr(1e300 * 1e300), "inf")
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self.assertEqual(repr(-1e300 * 1e300), "-inf")
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self.assertEqual(str(1e300 * 1e300), "inf")
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self.assertEqual(str(-1e300 * 1e300), "-inf")
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def test_nan_from_str(self):
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self.assert_(isnan(float("nan")))
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self.assert_(isnan(float("+nan")))
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self.assert_(isnan(float("-nan")))
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self.assertEqual(repr(float("nan")), "nan")
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self.assertEqual(repr(float("+nan")), "nan")
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self.assertEqual(repr(float("-nan")), "nan")
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self.assertEqual(repr(float("NAN")), "nan")
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self.assertEqual(repr(float("+NAn")), "nan")
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self.assertEqual(repr(float("-NaN")), "nan")
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self.assertEqual(str(float("nan")), "nan")
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self.assertEqual(str(float("+nan")), "nan")
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self.assertEqual(str(float("-nan")), "nan")
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self.assertRaises(ValueError, float, "nana")
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self.assertRaises(ValueError, float, "+nana")
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self.assertRaises(ValueError, float, "-nana")
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self.assertRaises(ValueError, float, "na")
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self.assertRaises(ValueError, float, "+na")
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self.assertRaises(ValueError, float, "-na")
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def test_nan_as_str(self):
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self.assertEqual(repr(1e300 * 1e300 * 0), "nan")
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self.assertEqual(repr(-1e300 * 1e300 * 0), "nan")
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self.assertEqual(str(1e300 * 1e300 * 0), "nan")
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self.assertEqual(str(-1e300 * 1e300 * 0), "nan")
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def test_main():
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test_support.run_unittest(
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FormatFunctionsTestCase,
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UnknownFormatTestCase,
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IEEEFormatTestCase,
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ReprTestCase,
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InfNanTest,
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)
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if __name__ == '__main__':
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test_main()
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