1import 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,):
22                for i in list(range(-10, 0)) + list(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, 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 == int:
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_powfloat(self):
63        self.powtest(float)
64
65    def test_other(self):
66        # Other tests-- not very systematic
67        self.assertEqual(pow(3,3) % 8, pow(3,3,8))
68        self.assertEqual(pow(3,3) % -8, pow(3,3,-8))
69        self.assertEqual(pow(3,2) % -2, pow(3,2,-2))
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(5,2) % -8, pow(5,2,-8))
73
74        self.assertEqual(pow(3,3) % 8, pow(3,3,8))
75        self.assertEqual(pow(3,3) % -8, pow(3,3,-8))
76        self.assertEqual(pow(3,2) % -2, pow(3,2,-2))
77        self.assertEqual(pow(-3,3) % 8, pow(-3,3,8))
78        self.assertEqual(pow(-3,3) % -8, pow(-3,3,-8))
79        self.assertEqual(pow(5,2) % -8, pow(5,2,-8))
80
81        for i in range(-10, 11):
82            for j in range(0, 6):
83                for k in range(-7, 11):
84                    if j >= 0 and k != 0:
85                        self.assertEqual(
86                            pow(i,j) % k,
87                            pow(i,j,k)
88                        )
89                    if j >= 0 and k != 0:
90                        self.assertEqual(
91                            pow(int(i),j) % k,
92                            pow(int(i),j,k)
93                        )
94
95    def test_bug643260(self):
96        class TestRpow:
97            def __rpow__(self, other):
98                return None
99        None ** TestRpow() # Won't fail when __rpow__ invoked.  SF bug #643260.
100
101    def test_bug705231(self):
102        # -1.0 raised to an integer should never blow up.  It did if the
103        # platform pow() was buggy, and Python didn't worm around it.
104        eq = self.assertEqual
105        a = -1.0
106        # The next two tests can still fail if the platform floor()
107        # function doesn't treat all large inputs as integers
108        # test_math should also fail if that is happening
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
122if __name__ == "__main__":
123    unittest.main()
124