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| -rw-r--r-- | Lib/test/test_float.py | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py index ddaf7bd..ff9cfee 100644 --- a/Lib/test/test_float.py +++ b/Lib/test/test_float.py @@ -563,6 +563,55 @@ class ReprTestCase(unittest.TestCase): 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))) + @unittest.skipUnless(float.__getformat__("double").startswith("IEEE"), "test requires IEEE 754 doubles") class RoundTestCase(unittest.TestCase): |