1import test.test_support, unittest
2
3class PowTest(unittest.TestCase):
4
5    def powtest(self, type):
6        if type != float:
7            for i in range(-1000, 1000):
8                self.assertEqual(pow(type(i), 0), 1)
9                self.assertEqual(pow(type(i), 1), type(i))
10                self.assertEqual(pow(type(0), 1), type(0))
11                self.assertEqual(pow(type(1), 1), type(1))
12
13            for i in range(-100, 100):
14                self.assertEqual(pow(type(i), 3), i*i*i)
15
16            pow2 = 1
17            for i in range(0,31):
18                self.assertEqual(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.assertEqual(pow(3,3) % 8, pow(3,3,8))
71        self.assertEqual(pow(3,3) % -8, pow(3,3,-8))
72        self.assertEqual(pow(3,2) % -2, pow(3,2,-2))
73        self.assertEqual(pow(-3,3) % 8, pow(-3,3,8))
74        self.assertEqual(pow(-3,3) % -8, pow(-3,3,-8))
75        self.assertEqual(pow(5,2) % -8, pow(5,2,-8))
76
77        self.assertEqual(pow(3L,3L) % 8, pow(3L,3L,8))
78        self.assertEqual(pow(3L,3L) % -8, pow(3L,3L,-8))
79        self.assertEqual(pow(3L,2) % -2, pow(3L,2,-2))
80        self.assertEqual(pow(-3L,3L) % 8, pow(-3L,3L,8))
81        self.assertEqual(pow(-3L,3L) % -8, pow(-3L,3L,-8))
82        self.assertEqual(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.assertEqual(
89                            pow(i,j) % k,
90                            pow(i,j,k)
91                        )
92                    if j >= 0 and k != 0:
93                        self.assertEqual(
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.assertEqual
108        a = -1.0
109        # The next two tests can still fail if the platform floor()
110        # function doesn't treat all large inputs as integers
111        # test_math should also fail if that is happening
112        eq(pow(a, 1.23e167), 1.0)
113        eq(pow(a, -1.23e167), 1.0)
114        for b in range(-10, 11):
115            eq(pow(a, float(b)), b & 1 and -1.0 or 1.0)
116        for n in range(0, 100):
117            fiveto = float(5 ** n)
118            # For small n, fiveto will be odd.  Eventually we run out of
119            # mantissa bits, though, and thereafer fiveto will be even.
120            expected = fiveto % 2.0 and -1.0 or 1.0
121            eq(pow(a, fiveto), expected)
122            eq(pow(a, -fiveto), expected)
123        eq(expected, 1.0)   # else we didn't push fiveto to evenness
124
125def test_main():
126    test.test_support.run_unittest(PowTest)
127
128if __name__ == "__main__":
129    test_main()
130