1 import test.test_support, unittest

     2 

     3 class PowTest(unittest.TestCase):

     4 

     5     def powtest(self, type):

     6         if type != float:

     7             for i in range(-1000, 1000):

     8                 self.assertEquals(pow(type(i), 0), 1)

     9                 self.assertEquals(pow(type(i), 1), type(i))

    10                 self.assertEquals(pow(type(0), 1), type(0))

    11                 self.assertEquals(pow(type(1), 1), type(1))

    12 

    13             for i in range(-100, 100):

    14                 self.assertEquals(pow(type(i), 3), i*i*i)

    15 

    16             pow2 = 1

    17             for i in range(0,31):

    18                 self.assertEquals(pow(2, i), pow2)

    19                 if i != 30 : pow2 = pow2*2

    20 

    21             for othertype in int, long:

    22                 for i in range(-10, 0) + range(1, 10):

    23                     ii = type(i)

    24                     for j in range(1, 11):

    25                         jj = -othertype(j)

    26                         pow(ii, jj)

    27 

    28         for othertype in int, long, float:

    29             for i in range(1, 100):

    30                 zero = type(0)

    31                 exp = -othertype(i/10.0)

    32                 if exp == 0:

    33                     continue

    34                 self.assertRaises(ZeroDivisionError, pow, zero, exp)

    35 

    36         il, ih = -20, 20

    37         jl, jh = -5,   5

    38         kl, kh = -10, 10

    39         asseq = self.assertEqual

    40         if type == float:

    41             il = 1

    42             asseq = self.assertAlmostEqual

    43         elif type == int:

    44             jl = 0

    45         elif type == long:

    46             jl, jh = 0, 15

    47         for i in range(il, ih+1):

    48             for j in range(jl, jh+1):

    49                 for k in range(kl, kh+1):

    50                     if k != 0:

    51                         if type == float or j < 0:

    52                             self.assertRaises(TypeError, pow, type(i), j, k)

    53                             continue

    54                         asseq(

    55                             pow(type(i),j,k),

    56                             pow(type(i),j)% type(k)

    57                         )

    58 

    59     def test_powint(self):

    60         self.powtest(int)

    61 

    62     def test_powlong(self):

    63         self.powtest(long)

    64 

    65     def test_powfloat(self):

    66         self.powtest(float)

    67 

    68     def test_other(self):

    69         # Other tests-- not very systematic

    70         self.assertEquals(pow(3,3) % 8, pow(3,3,8))

    71         self.assertEquals(pow(3,3) % -8, pow(3,3,-8))

    72         self.assertEquals(pow(3,2) % -2, pow(3,2,-2))

    73         self.assertEquals(pow(-3,3) % 8, pow(-3,3,8))

    74         self.assertEquals(pow(-3,3) % -8, pow(-3,3,-8))

    75         self.assertEquals(pow(5,2) % -8, pow(5,2,-8))

    76 

    77         self.assertEquals(pow(3L,3L) % 8, pow(3L,3L,8))

    78         self.assertEquals(pow(3L,3L) % -8, pow(3L,3L,-8))

    79         self.assertEquals(pow(3L,2) % -2, pow(3L,2,-2))

    80         self.assertEquals(pow(-3L,3L) % 8, pow(-3L,3L,8))

    81         self.assertEquals(pow(-3L,3L) % -8, pow(-3L,3L,-8))

    82         self.assertEquals(pow(5L,2) % -8, pow(5L,2,-8))

    83 

    84         for i in range(-10, 11):

    85             for j in range(0, 6):

    86                 for k in range(-7, 11):

    87                     if j >= 0 and k != 0:

    88                         self.assertEquals(

    89                             pow(i,j) % k,

    90                             pow(i,j,k)

    91                         )

    92                     if j >= 0 and k != 0:

    93                         self.assertEquals(

    94                             pow(long(i),j) % k,

    95                             pow(long(i),j,k)

    96                         )

    97 

    98     def test_bug643260(self):

    99         class TestRpow:

   100             def __rpow__(self, other):

   101                 return None

   102         None ** TestRpow() # Won't fail when __rpow__ invoked.  SF bug #643260.

   103 

   104     def test_bug705231(self):

   105         # -1.0 raised to an integer should never blow up.  It did if the

   106         # platform pow() was buggy, and Python didn't worm around it.

   107         eq = self.assertEquals

   108         a = -1.0

   109         eq(pow(a, 1.23e167), 1.0)

   110         eq(pow(a, -1.23e167), 1.0)

   111         for b in range(-10, 11):

   112             eq(pow(a, float(b)), b & 1 and -1.0 or 1.0)

   113         for n in range(0, 100):

   114             fiveto = float(5 ** n)

   115             # For small n, fiveto will be odd.  Eventually we run out of

   116             # mantissa bits, though, and thereafer fiveto will be even.

   117             expected = fiveto % 2.0 and -1.0 or 1.0

   118             eq(pow(a, fiveto), expected)

   119             eq(pow(a, -fiveto), expected)

   120         eq(expected, 1.0)   # else we didn't push fiveto to evenness

   121 

   122 def test_main():

   123     test.test_support.run_unittest(PowTest)

   124 

   125 if __name__ == "__main__":

   126     test_main()