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cpython/Lib/test/test_random.py
Brett Cannon 672237dc6c warnings.catch_warnings() now returns a list or None instead of the custom 
WarningsRecorder object. This makes the API simpler to use as no special object
must be learned.

Closes issue 3781.
Review by Benjamin Peterson.
2008-09-09 00:49:16 +00:00

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#!/usr/bin/env python
import unittest
import random
import time
import pickle
import warnings
from math import log, exp, sqrt, pi, fsum as msum
from test import test_support
class TestBasicOps(unittest.TestCase):
# Superclass with tests common to all generators.
# Subclasses must arrange for self.gen to retrieve the Random instance
# to be tested.
def randomlist(self, n):
"""Helper function to make a list of random numbers"""
return [self.gen.random() for i in xrange(n)]
def test_autoseed(self):
self.gen.seed()
state1 = self.gen.getstate()
time.sleep(0.1)
self.gen.seed() # diffent seeds at different times
state2 = self.gen.getstate()
self.assertNotEqual(state1, state2)
def test_saverestore(self):
N = 1000
self.gen.seed()
state = self.gen.getstate()
randseq = self.randomlist(N)
self.gen.setstate(state) # should regenerate the same sequence
self.assertEqual(randseq, self.randomlist(N))
def test_seedargs(self):
for arg in [None, 0, 0L, 1, 1L, -1, -1L, 10**20, -(10**20),
3.14, 1+2j, 'a', tuple('abc')]:
self.gen.seed(arg)
for arg in [range(3), dict(one=1)]:
self.assertRaises(TypeError, self.gen.seed, arg)
self.assertRaises(TypeError, self.gen.seed, 1, 2)
self.assertRaises(TypeError, type(self.gen), [])
def test_jumpahead(self):
self.gen.seed()
state1 = self.gen.getstate()
self.gen.jumpahead(100)
state2 = self.gen.getstate() # s/b distinct from state1
self.assertNotEqual(state1, state2)
self.gen.jumpahead(100)
state3 = self.gen.getstate() # s/b distinct from state2
self.assertNotEqual(state2, state3)
self.assertRaises(TypeError, self.gen.jumpahead) # needs an arg
self.assertRaises(TypeError, self.gen.jumpahead, "ick") # wrong type
self.assertRaises(TypeError, self.gen.jumpahead, 2.3) # wrong type
self.assertRaises(TypeError, self.gen.jumpahead, 2, 3) # too many
def test_sample(self):
# For the entire allowable range of 0 <= k <= N, validate that
# the sample is of the correct length and contains only unique items
N = 100
population = xrange(N)
for k in xrange(N+1):
s = self.gen.sample(population, k)
self.assertEqual(len(s), k)
uniq = set(s)
self.assertEqual(len(uniq), k)
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 reduce(int.__mul__, xrange(1, 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_sample_inputs(self):
# SF bug #801342 -- population can be any iterable defining __len__()
self.gen.sample(set(range(20)), 2)
self.gen.sample(range(20), 2)
self.gen.sample(xrange(20), 2)
self.gen.sample(str('abcdefghijklmnopqrst'), 2)
self.gen.sample(tuple('abcdefghijklmnopqrst'), 2)
def test_sample_on_dicts(self):
self.gen.sample(dict.fromkeys('abcdefghijklmnopqrst'), 2)
# SF bug #1460340 -- random.sample can raise KeyError
a = dict.fromkeys(range(10)+range(10,100,2)+range(100,110))
self.gen.sample(a, 3)
# A followup to bug #1460340: sampling from a dict could return
# a subset of its keys or of its values, depending on the size of
# the subset requested.
N = 30
d = dict((i, complex(i, i)) for i in xrange(N))
for k in xrange(N+1):
samp = self.gen.sample(d, k)
# Verify that we got ints back (keys); the values are complex.
for x in samp:
self.assert_(type(x) is int)
samp.sort()
self.assertEqual(samp, range(N))
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
# by (and only by) the .gauss() method.
for seed in 1, 12, 123, 1234, 12345, 123456, 654321:
self.gen.seed(seed)
x1 = self.gen.random()
y1 = self.gen.gauss(0, 1)
self.gen.seed(seed)
x2 = self.gen.random()
y2 = self.gen.gauss(0, 1)
self.assertEqual(x1, x2)
self.assertEqual(y1, y2)
def test_pickling(self):
state = pickle.dumps(self.gen)
origseq = [self.gen.random() for i in xrange(10)]
newgen = pickle.loads(state)
restoredseq = [newgen.random() for i in xrange(10)]
self.assertEqual(origseq, restoredseq)
def test_bug_1727780(self):
# verify that version-2-pickles can be loaded
# fine, whether they are created on 32-bit or 64-bit
# platforms, and that version-3-pickles load fine.
files = [("randv2_32.pck", 780),
("randv2_64.pck", 866),
("randv3.pck", 343)]
for file, value in files:
f = open(test_support.findfile(file),"rb")
r = pickle.load(f)
f.close()
self.assertEqual(r.randrange(1000), value)
class WichmannHill_TestBasicOps(TestBasicOps):
gen = random.WichmannHill()
def test_setstate_first_arg(self):
self.assertRaises(ValueError, self.gen.setstate, (2, None, None))
def test_strong_jumpahead(self):
# tests that jumpahead(n) semantics correspond to n calls to random()
N = 1000
s = self.gen.getstate()
self.gen.jumpahead(N)
r1 = self.gen.random()
# now do it the slow way
self.gen.setstate(s)
for i in xrange(N):
self.gen.random()
r2 = self.gen.random()
self.assertEqual(r1, r2)
def test_gauss_with_whseed(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
# by (and only by) the .gauss() method.
for seed in 1, 12, 123, 1234, 12345, 123456, 654321:
self.gen.whseed(seed)
x1 = self.gen.random()
y1 = self.gen.gauss(0, 1)
self.gen.whseed(seed)
x2 = self.gen.random()
y2 = self.gen.gauss(0, 1)
self.assertEqual(x1, x2)
self.assertEqual(y1, y2)
def test_bigrand(self):
# Verify warnings are raised when randrange is too large for random()
with warnings.catch_warnings():
warnings.filterwarnings("error", "Underlying random")
self.assertRaises(UserWarning, self.gen.randrange, 2**60)
class SystemRandom_TestBasicOps(TestBasicOps):
gen = random.SystemRandom()
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()
def test_setstate_first_arg(self):
self.assertRaises(ValueError, self.gen.setstate, (1, None, None))
def test_setstate_middle_arg(self):
# Wrong type, s/b tuple
self.assertRaises(TypeError, self.gen.setstate, (2, None, None))
# Wrong length, s/b 625
self.assertRaises(ValueError, self.gen.setstate, (2, (1,2,3), None))
# Wrong type, s/b tuple of 625 ints
self.assertRaises(TypeError, self.gen.setstate, (2, ('a',)*625, None))
# Last element s/b an int also
self.assertRaises(TypeError, self.gen.setstate, (2, (0,)*624+('a',), None))
def test_referenceImplementation(self):
# Compare the python implementation with results from the original
# code. Create 2000 53-bit precision random floats. Compare only
# the last ten entries to show that the independent implementations
# are tracking. Here is the main() function needed to create the
# list of expected random numbers:
# void main(void){
# int i;
# unsigned long init[4]={61731, 24903, 614, 42143}, length=4;
# init_by_array(init, length);
# for (i=0; i<2000; i++) {
# printf("%.15f ", genrand_res53());
# if (i%5==4) printf("\n");
# }
# }
expected = [0.45839803073713259,
0.86057815201978782,
0.92848331726782152,
0.35932681119782461,
0.081823493762449573,
0.14332226470169329,
0.084297823823520024,
0.53814864671831453,
0.089215024911993401,
0.78486196105372907]
self.gen.seed(61731L + (24903L<<32) + (614L<<64) + (42143L<<96))
actual = self.randomlist(2000)[-10:]
for a, e in zip(actual, expected):
self.assertAlmostEqual(a,e,places=14)
def test_strong_reference_implementation(self):
# Like test_referenceImplementation, but checks for exact bit-level
# equality. This should pass on any box where C double contains
# at least 53 bits of precision (the underlying algorithm suffers
# no rounding errors -- all results are exact).
from math import ldexp
expected = [0x0eab3258d2231fL,
0x1b89db315277a5L,
0x1db622a5518016L,
0x0b7f9af0d575bfL,
0x029e4c4db82240L,
0x04961892f5d673L,
0x02b291598e4589L,
0x11388382c15694L,
0x02dad977c9e1feL,
0x191d96d4d334c6L]
self.gen.seed(61731L + (24903L<<32) + (614L<<64) + (42143L<<96))
actual = self.randomlist(2000)[-10:]
for a, e in zip(actual, expected):
self.assertEqual(long(ldexp(a, 53)), e)
def test_long_seed(self):
# This is most interesting to run in debug mode, just to make sure
# nothing blows up. Under the covers, a dynamically resized array
# is allocated, consuming space proportional to the number of bits
# in the seed. Unfortunately, that's a quadratic-time algorithm,
# so don't make this horribly big.
seed = (1L << (10000 * 8)) - 1 # about 10K bytes
self.gen.seed(seed)
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 cross-platform repeatability
self.gen.seed(1234567)
self.assertEqual(self.gen.getrandbits(100),
97904845777343510404718956115L)
# 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, 'a')
self.assertRaises(TypeError, self.gen.getrandbits, 1, 2)
self.assertRaises(ValueError, self.gen.getrandbits, 0)
self.assertRaises(ValueError, self.gen.getrandbits, -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
def test_randrange_bug_1590891(self):
start = 1000000000000
stop = -100000000000000000000
step = -200
x = self.gen.randrange(start, stop, step)
self.assert_(stop < x <= start)
self.assertEqual((x+stop)%step, 0)
_gammacoeff = (0.9999999999995183, 676.5203681218835, -1259.139216722289,
771.3234287757674, -176.6150291498386, 12.50734324009056,
-0.1385710331296526, 0.9934937113930748e-05, 0.1659470187408462e-06)
def gamma(z, cof=_gammacoeff, g=7):
z -= 1.0
s = msum([cof[0]] + [cof[i] / (z+i) for i in range(1,len(cof))])
z += 0.5
return (z+g)**z / exp(z+g) * sqrt(2.0*pi) * s
class TestDistributions(unittest.TestCase):
def test_zeroinputs(self):
# Verify that distributions can handle a series of zero inputs'
g = random.Random()
x = [g.random() for i in xrange(50)] + [0.0]*5
g.random = x[:].pop; g.uniform(1,10)
g.random = x[:].pop; g.paretovariate(1.0)
g.random = x[:].pop; g.expovariate(1.0)
g.random = x[:].pop; g.weibullvariate(1.0, 1.0)
g.random = x[:].pop; g.normalvariate(0.0, 1.0)
g.random = x[:].pop; g.gauss(0.0, 1.0)
g.random = x[:].pop; g.lognormvariate(0.0, 1.0)
g.random = x[:].pop; g.vonmisesvariate(0.0, 1.0)
g.random = x[:].pop; g.gammavariate(0.01, 1.0)
g.random = x[:].pop; g.gammavariate(1.0, 1.0)
g.random = x[:].pop; g.gammavariate(200.0, 1.0)
g.random = x[:].pop; g.betavariate(3.0, 3.0)
g.random = x[:].pop; g.triangular(0.0, 1.0, 1.0/3.0)
def test_avg_std(self):
# Use integration to test distribution average and standard deviation.
# Only works for distributions which do not consume variates in pairs
g = random.Random()
N = 5000
x = [i/float(N) for i in xrange(1,N)]
for variate, args, mu, sigmasqrd in [
(g.uniform, (1.0,10.0), (10.0+1.0)/2, (10.0-1.0)**2/12),
(g.triangular, (0.0, 1.0, 1.0/3.0), 4.0/9.0, 7.0/9.0/18.0),
(g.expovariate, (1.5,), 1/1.5, 1/1.5**2),
(g.paretovariate, (5.0,), 5.0/(5.0-1),
5.0/((5.0-1)**2*(5.0-2))),
(g.weibullvariate, (1.0, 3.0), gamma(1+1/3.0),
gamma(1+2/3.0)-gamma(1+1/3.0)**2) ]:
g.random = x[:].pop
y = []
for i in xrange(len(x)):
try:
y.append(variate(*args))
except IndexError:
pass
s1 = s2 = 0
for e in y:
s1 += e
s2 += (e - mu) ** 2
N = len(y)
self.assertAlmostEqual(s1/N, mu, 2)
self.assertAlmostEqual(s2/(N-1), sigmasqrd, 2)
class TestModule(unittest.TestCase):
def testMagicConstants(self):
self.assertAlmostEqual(random.NV_MAGICCONST, 1.71552776992141)
self.assertAlmostEqual(random.TWOPI, 6.28318530718)
self.assertAlmostEqual(random.LOG4, 1.38629436111989)
self.assertAlmostEqual(random.SG_MAGICCONST, 2.50407739677627)
def test__all__(self):
# tests validity but not completeness of the __all__ list
self.failUnless(set(random.__all__) <= set(dir(random)))
def test_random_subclass_with_kwargs(self):
# SF bug #1486663 -- this used to erroneously raise a TypeError
class Subclass(random.Random):
def __init__(self, newarg=None):
random.Random.__init__(self)
Subclass(newarg=1)
def test_main(verbose=None):
testclasses = [WichmannHill_TestBasicOps,
MersenneTwister_TestBasicOps,
TestDistributions,
TestModule]
try:
random.SystemRandom().random()
except NotImplementedError:
pass
else:
testclasses.append(SystemRandom_TestBasicOps)
test_support.run_unittest(*testclasses)
# verify reference counting
import sys
if verbose and hasattr(sys, "gettotalrefcount"):
counts = [None] * 5
for i in xrange(len(counts)):
test_support.run_unittest(*testclasses)
counts[i] = sys.gettotalrefcount()
print counts
if __name__ == "__main__":
test_main(verbose=True)
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