diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/random.py | 5 | ||||
| -rw-r--r-- | Lib/test/test_random.py | 27 |
2 files changed, 22 insertions, 10 deletions
diff --git a/Lib/random.py b/Lib/random.py index 3db1f1a..2d4859c 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -743,9 +743,6 @@ def _test_generator(n, funccall): print 'avg %g, stddev %g, min %g, max %g' % \ (avg, stddev, smallest, largest) -def _sample_generator(n, k): - # Return a fixed element from the sample. Validates random ordering. - return sample(xrange(n), k)[k//2] def _test(N=2000): _test_generator(N, 'random()') @@ -764,8 +761,6 @@ def _test(N=2000): _test_generator(N, 'gammavariate(200.0, 1.0)') _test_generator(N, 'gauss(0.0, 1.0)') _test_generator(N, 'betavariate(3.0, 3.0)') - _test_generator(N, '_sample_generator(50, 5)') # expected s.d.: 14.4 - _test_generator(N, '_sample_generator(50, 45)') # expected s.d.: 14.4 # Create one instance, seeded from current time, and export its methods # as module-level functions. The functions share state across all uses diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py index 1f6abfe..cc9b44e 100644 --- a/Lib/test/test_random.py +++ b/Lib/test/test_random.py @@ -4,6 +4,7 @@ import unittest import random import time from math import log, exp, sqrt, pi +from sets import Set from test import test_support class TestBasicOps(unittest.TestCase): @@ -61,11 +62,29 @@ class TestBasicOps(unittest.TestCase): for k in xrange(N+1): s = self.gen.sample(population, k) self.assertEqual(len(s), k) - uniq = dict.fromkeys(s) + uniq = Set(s) self.assertEqual(len(uniq), k) - self.failIf(None in uniq) + self.failUnless(uniq <= Set(population)) self.assertEqual(self.gen.sample([], 0), []) # test edge case N==k==0 + def test_sample_distribution(self): + # For the entire allowable range of 0 <= k <= N, validate that + # sample generates all possible permutations + n = 5 + pop = range(n) + trials = 10000 # large num prevents false negatives without slowing normal case + def factorial(n): + return n==0 and 1 or n * factorial(n-1) + for k in xrange(n): + expected = factorial(n) / factorial(n-k) + perms = {} + for i in xrange(trials): + perms[tuple(self.gen.sample(pop, k))] = None + if len(perms) == expected: + break + else: + self.fail() + def test_gauss(self): # Ensure that the seed() method initializes all the hidden state. In # particular, through 2.2.1 it failed to reset a piece of state used @@ -250,9 +269,7 @@ class TestModule(unittest.TestCase): def test__all__(self): # tests validity but not completeness of the __all__ list - defined = dict.fromkeys(dir(random)) - for entry in random.__all__: - self.failUnless(entry in defined) + self.failUnless(Set(random.__all__) <= Set(dir(random))) def test_main(): suite = unittest.TestSuite() |