diff options
Diffstat (limited to 'Lib/test/test_pow.py')
| -rw-r--r-- | Lib/test/test_pow.py | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Lib/test/test_pow.py b/Lib/test/test_pow.py index 660ff80bbf..5cea9ceb20 100644 --- a/Lib/test/test_pow.py +++ b/Lib/test/test_pow.py @@ -93,6 +93,28 @@ class PowTest(unittest.TestCase): pow(int(i),j,k) ) + def test_big_exp(self): + import random + self.assertEqual(pow(2, 50000), 1 << 50000) + # Randomized modular tests, checking the identities + # a**(b1 + b2) == a**b1 * a**b2 + # a**(b1 * b2) == (a**b1)**b2 + prime = 1000000000039 # for speed, relatively small prime modulus + for i in range(10): + a = random.randrange(1000, 1000000) + bpower = random.randrange(1000, 50000) + b = random.randrange(1 << (bpower - 1), 1 << bpower) + b1 = random.randrange(1, b) + b2 = b - b1 + got1 = pow(a, b, prime) + got2 = pow(a, b1, prime) * pow(a, b2, prime) % prime + if got1 != got2: + self.fail(f"{a=:x} {b1=:x} {b2=:x} {got1=:x} {got2=:x}") + got3 = pow(a, b1 * b2, prime) + got4 = pow(pow(a, b1, prime), b2, prime) + if got3 != got4: + self.fail(f"{a=:x} {b1=:x} {b2=:x} {got3=:x} {got4=:x}") + def test_bug643260(self): class TestRpow: def __rpow__(self, other): |