1 from __future__ import division

     2 # When true division is the default, get rid of this and add it to

     3 # test_long.py instead.  In the meantime, it's too obscure to try to

     4 # trick just part of test_long into using future division.

     5 

     6 import unittest

     7 from test.test_support import run_unittest

     8 

     9 class TrueDivisionTests(unittest.TestCase):

    10     def test(self):

    11         huge = 1L << 40000

    12         mhuge = -huge

    13         self.assertEqual(huge / huge, 1.0)

    14         self.assertEqual(mhuge / mhuge, 1.0)

    15         self.assertEqual(huge / mhuge, -1.0)

    16         self.assertEqual(mhuge / huge, -1.0)

    17         self.assertEqual(1 / huge, 0.0)

    18         self.assertEqual(1L / huge, 0.0)

    19         self.assertEqual(1 / mhuge, 0.0)

    20         self.assertEqual(1L / mhuge, 0.0)

    21         self.assertEqual((666 * huge + (huge >> 1)) / huge, 666.5)

    22         self.assertEqual((666 * mhuge + (mhuge >> 1)) / mhuge, 666.5)

    23         self.assertEqual((666 * huge + (huge >> 1)) / mhuge, -666.5)

    24         self.assertEqual((666 * mhuge + (mhuge >> 1)) / huge, -666.5)

    25         self.assertEqual(huge / (huge << 1), 0.5)

    26         self.assertEqual((1000000 * huge) / huge, 1000000)

    27 

    28         namespace = {'huge': huge, 'mhuge': mhuge}

    29 

    30         for overflow in ["float(huge)", "float(mhuge)",

    31                          "huge / 1", "huge / 2L", "huge / -1", "huge / -2L",

    32                          "mhuge / 100", "mhuge / 100L"]:

    33             # XXX(cwinter) this test doesn't pass when converted to

    34             # use assertRaises.

    35             try:

    36                 eval(overflow, namespace)

    37                 self.fail("expected OverflowError from %r" % overflow)

    38             except OverflowError:

    39                 pass

    40 

    41         for underflow in ["1 / huge", "2L / huge", "-1 / huge", "-2L / huge",

    42                          "100 / mhuge", "100L / mhuge"]:

    43             result = eval(underflow, namespace)

    44             self.assertEqual(result, 0.0,

    45                              "expected underflow to 0 from %r" % underflow)

    46 

    47         for zero in ["huge / 0", "huge / 0L", "mhuge / 0", "mhuge / 0L"]:

    48             self.assertRaises(ZeroDivisionError, eval, zero, namespace)

    49 

    50 

    51 def test_main():

    52     run_unittest(TrueDivisionTests)

    53 

    54 if __name__ == "__main__":

    55     test_main()