[Python-checkins] python/dist/src/Lib/test test_random.py, 1.17,
1.18
rhettinger at users.sourceforge.net
rhettinger at users.sourceforge.net
Mon Aug 30 08:15:03 CEST 2004
Update of /cvsroot/python/python/dist/src/Lib/test
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv26687/Lib/test
Modified Files:
test_random.py
Log Message:
Teach the random module about os.urandom().
* Use it for seeding when it is available.
* Provide an alternate generator based on it.
Index: test_random.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_random.py,v
retrieving revision 1.17
retrieving revision 1.18
diff -u -d -r1.17 -r1.18
--- test_random.py 9 Jul 2004 14:26:18 -0000 1.17
+++ test_random.py 30 Aug 2004 06:14:30 -0000 1.18
@@ -164,6 +164,107 @@
self.assertRaises(UserWarning, self.gen.randrange, 2**60)
warnings.filters[:] = oldfilters
+class HardwareRandom_TestBasicOps(TestBasicOps):
+ gen = random.HardwareRandom()
+
+ def test_autoseed(self):
+ # Doesn't need to do anything except not fail
+ self.gen.seed()
+
+ def test_saverestore(self):
+ self.assertRaises(NotImplementedError, self.gen.getstate)
+ self.assertRaises(NotImplementedError, self.gen.setstate, None)
+
+ def test_seedargs(self):
+ # Doesn't need to do anything except not fail
+ self.gen.seed(100)
+
+ def test_jumpahead(self):
+ # Doesn't need to do anything except not fail
+ self.gen.jumpahead(100)
+
+ def test_gauss(self):
+ self.gen.gauss_next = None
+ self.gen.seed(100)
+ self.assertEqual(self.gen.gauss_next, None)
+
+ def test_pickling(self):
+ self.assertRaises(NotImplementedError, pickle.dumps, self.gen)
+
+ def test_53_bits_per_float(self):
+ # This should pass whenever a C double has 53 bit precision.
+ span = 2 ** 53
+ cum = 0
+ for i in xrange(100):
+ cum |= int(self.gen.random() * span)
+ self.assertEqual(cum, span-1)
+
+ def test_bigrand(self):
+ # The randrange routine should build-up the required number of bits
+ # in stages so that all bit positions are active.
+ span = 2 ** 500
+ cum = 0
+ for i in xrange(100):
+ r = self.gen.randrange(span)
+ self.assert_(0 <= r < span)
+ cum |= r
+ self.assertEqual(cum, span-1)
+
+ def test_bigrand_ranges(self):
+ for i in [40,80, 160, 200, 211, 250, 375, 512, 550]:
+ start = self.gen.randrange(2 ** i)
+ stop = self.gen.randrange(2 ** (i-2))
+ if stop <= start:
+ return
+ self.assert_(start <= self.gen.randrange(start, stop) < stop)
+
+ def test_rangelimits(self):
+ for start, stop in [(-2,0), (-(2**60)-2,-(2**60)), (2**60,2**60+2)]:
+ self.assertEqual(set(range(start,stop)),
+ set([self.gen.randrange(start,stop) for i in xrange(100)]))
+
+ def test_genrandbits(self):
+ # Verify ranges
+ for k in xrange(1, 1000):
+ self.assert_(0 <= self.gen.getrandbits(k) < 2**k)
+
+ # Verify all bits active
+ getbits = self.gen.getrandbits
+ for span in [1, 2, 3, 4, 31, 32, 32, 52, 53, 54, 119, 127, 128, 129]:
+ cum = 0
+ for i in xrange(100):
+ cum |= getbits(span)
+ self.assertEqual(cum, 2**span-1)
+
+ # Verify argument checking
+ self.assertRaises(TypeError, self.gen.getrandbits)
+ self.assertRaises(TypeError, self.gen.getrandbits, 1, 2)
+ self.assertRaises(ValueError, self.gen.getrandbits, 0)
+ self.assertRaises(ValueError, self.gen.getrandbits, -1)
+ self.assertRaises(TypeError, self.gen.getrandbits, 10.1)
+
+ def test_randbelow_logic(self, _log=log, int=int):
+ # check bitcount transition points: 2**i and 2**(i+1)-1
+ # show that: k = int(1.001 + _log(n, 2))
+ # is equal to or one greater than the number of bits in n
+ for i in xrange(1, 1000):
+ n = 1L << i # check an exact power of two
+ numbits = i+1
+ k = int(1.00001 + _log(n, 2))
+ self.assertEqual(k, numbits)
+ self.assert_(n == 2**(k-1))
+
+ n += n - 1 # check 1 below the next power of two
+ k = int(1.00001 + _log(n, 2))
+ self.assert_(k in [numbits, numbits+1])
+ self.assert_(2**k > n > 2**(k-2))
+
+ n -= n >> 15 # check a little farther below the next power of two
+ k = int(1.00001 + _log(n, 2))
+ self.assertEqual(k, numbits) # note the stronger assertion
+ self.assert_(2**k > n > 2**(k-1)) # note the stronger assertion
+
+
class MersenneTwister_TestBasicOps(TestBasicOps):
gen = random.Random()
@@ -391,6 +492,7 @@
def test_main(verbose=None):
testclasses = (WichmannHill_TestBasicOps,
MersenneTwister_TestBasicOps,
+ HardwareRandom_TestBasicOps,
TestDistributions,
TestModule)
test_support.run_unittest(*testclasses)
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