bpo-37798: Test both Python and C versions in test_statistics.py (GH-15453)

This commit is contained in:
Dong-hee Na 2019-08-25 02:51:20 +09:00 committed by Raymond Hettinger
parent edd21129dd
commit 8ad22a4226
2 changed files with 75 additions and 33 deletions

View file

@ -18,6 +18,7 @@
from decimal import Decimal
from fractions import Fraction
from test import support
# Module to be tested.
@ -178,6 +179,23 @@ class _DoNothing:
# We prefer this for testing numeric values that may not be exactly equal,
# and avoid using TestCase.assertAlmostEqual, because it sucks :-)
py_statistics = support.import_fresh_module('statistics', blocked=['_statistics'])
c_statistics = support.import_fresh_module('statistics', fresh=['_statistics'])
class TestModules(unittest.TestCase):
func_names = ['_normal_dist_inv_cdf']
def test_py_functions(self):
for fname in self.func_names:
self.assertEqual(getattr(py_statistics, fname).__module__, 'statistics')
@unittest.skipUnless(c_statistics, 'requires _statistics')
def test_c_functions(self):
for fname in self.func_names:
self.assertEqual(getattr(c_statistics, fname).__module__, '_statistics')
class NumericTestCase(unittest.TestCase):
"""Unit test class for numeric work.
@ -2314,7 +2332,7 @@ def test_error_cases(self):
quantiles([10, None, 30], n=4) # data is non-numeric
class TestNormalDist(unittest.TestCase):
class TestNormalDist:
# General note on precision: The pdf(), cdf(), and overlap() methods
# depend on functions in the math libraries that do not make
@ -2324,35 +2342,35 @@ class TestNormalDist(unittest.TestCase):
# implementing our own implementations from scratch.
def test_slots(self):
nd = statistics.NormalDist(300, 23)
nd = self.module.NormalDist(300, 23)
with self.assertRaises(TypeError):
vars(nd)
self.assertEqual(tuple(nd.__slots__), ('_mu', '_sigma'))
def test_instantiation_and_attributes(self):
nd = statistics.NormalDist(500, 17)
nd = self.module.NormalDist(500, 17)
self.assertEqual(nd.mean, 500)
self.assertEqual(nd.stdev, 17)
self.assertEqual(nd.variance, 17**2)
# default arguments
nd = statistics.NormalDist()
nd = self.module.NormalDist()
self.assertEqual(nd.mean, 0)
self.assertEqual(nd.stdev, 1)
self.assertEqual(nd.variance, 1**2)
# error case: negative sigma
with self.assertRaises(statistics.StatisticsError):
statistics.NormalDist(500, -10)
with self.assertRaises(self.module.StatisticsError):
self.module.NormalDist(500, -10)
# verify that subclass type is honored
class NewNormalDist(statistics.NormalDist):
class NewNormalDist(self.module.NormalDist):
pass
nnd = NewNormalDist(200, 5)
self.assertEqual(type(nnd), NewNormalDist)
def test_alternative_constructor(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
data = [96, 107, 90, 92, 110]
# list input
self.assertEqual(NormalDist.from_samples(data), NormalDist(99, 9))
@ -2361,9 +2379,9 @@ def test_alternative_constructor(self):
# iterator input
self.assertEqual(NormalDist.from_samples(iter(data)), NormalDist(99, 9))
# error cases
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
NormalDist.from_samples([]) # empty input
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
NormalDist.from_samples([10]) # only one input
# verify that subclass type is honored
@ -2373,7 +2391,7 @@ class NewNormalDist(NormalDist):
self.assertEqual(type(nnd), NewNormalDist)
def test_sample_generation(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
mu, sigma = 10_000, 3.0
X = NormalDist(mu, sigma)
n = 1_000
@ -2381,7 +2399,7 @@ def test_sample_generation(self):
self.assertEqual(len(data), n)
self.assertEqual(set(map(type, data)), {float})
# mean(data) expected to fall within 8 standard deviations
xbar = statistics.mean(data)
xbar = self.module.mean(data)
self.assertTrue(mu - sigma*8 <= xbar <= mu + sigma*8)
# verify that seeding makes reproducible sequences
@ -2395,7 +2413,7 @@ def test_sample_generation(self):
self.assertNotEqual(data1, data2)
def test_pdf(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
X = NormalDist(100, 15)
# Verify peak around center
self.assertLess(X.pdf(99), X.pdf(100))
@ -2426,7 +2444,7 @@ def test_pdf(self):
self.assertAlmostEqual(Z.pdf(-x / 100.0), px, places=4)
# Error case: variance is zero
Y = NormalDist(100, 0)
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
Y.pdf(90)
# Special values
self.assertEqual(X.pdf(float('-Inf')), 0.0)
@ -2434,7 +2452,7 @@ def test_pdf(self):
self.assertTrue(math.isnan(X.pdf(float('NaN'))))
def test_cdf(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
X = NormalDist(100, 15)
cdfs = [X.cdf(x) for x in range(1, 200)]
self.assertEqual(set(map(type, cdfs)), {float})
@ -2456,7 +2474,7 @@ def test_cdf(self):
self.assertAlmostEqual(Z.cdf(-z), 1.0 - cum_prob, places=5)
# Error case: variance is zero
Y = NormalDist(100, 0)
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
Y.cdf(90)
# Special values
self.assertEqual(X.cdf(float('-Inf')), 0.0)
@ -2465,7 +2483,7 @@ def test_cdf(self):
@support.skip_if_pgo_task
def test_inv_cdf(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
# Center case should be exact.
iq = NormalDist(100, 15)
@ -2513,15 +2531,15 @@ def test_inv_cdf(self):
self.assertAlmostEqual(iq.inv_cdf(iq.cdf(x)), x, places=5)
# Error cases:
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
iq.inv_cdf(0.0) # p is zero
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
iq.inv_cdf(-0.1) # p under zero
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
iq.inv_cdf(1.0) # p is one
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
iq.inv_cdf(1.1) # p over one
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
iq = NormalDist(100, 0) # sigma is zero
iq.inv_cdf(0.5)
@ -2529,7 +2547,7 @@ def test_inv_cdf(self):
self.assertTrue(math.isnan(Z.inv_cdf(float('NaN'))))
def test_overlap(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
# Match examples from Imman and Bradley
for X1, X2, published_result in [
@ -2586,26 +2604,26 @@ def overlap_numeric(X, Y, *, steps=8_192, z=5):
X.overlap(X, X) # too may arguments
with self.assertRaises(TypeError):
X.overlap(None) # right operand not a NormalDist
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
X.overlap(NormalDist(1, 0)) # right operand sigma is zero
with self.assertRaises(statistics.StatisticsError):
with self.assertRaises(self.module.StatisticsError):
NormalDist(1, 0).overlap(X) # left operand sigma is zero
def test_properties(self):
X = statistics.NormalDist(100, 15)
X = self.module.NormalDist(100, 15)
self.assertEqual(X.mean, 100)
self.assertEqual(X.stdev, 15)
self.assertEqual(X.variance, 225)
def test_same_type_addition_and_subtraction(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
X = NormalDist(100, 12)
Y = NormalDist(40, 5)
self.assertEqual(X + Y, NormalDist(140, 13)) # __add__
self.assertEqual(X - Y, NormalDist(60, 13)) # __sub__
def test_translation_and_scaling(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
X = NormalDist(100, 15)
y = 10
self.assertEqual(+X, NormalDist(100, 15)) # __pos__
@ -2621,7 +2639,7 @@ def test_translation_and_scaling(self):
y / X
def test_unary_operations(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
X = NormalDist(100, 12)
Y = +X
self.assertIsNot(X, Y)
@ -2633,7 +2651,7 @@ def test_unary_operations(self):
self.assertEqual(X.stdev, Y.stdev)
def test_equality(self):
NormalDist = statistics.NormalDist
NormalDist = self.module.NormalDist
nd1 = NormalDist()
nd2 = NormalDist(2, 4)
nd3 = NormalDist()
@ -2673,7 +2691,7 @@ def __init__(self, mu, sigma):
self.assertNotEqual(nd, lnd)
def test_pickle_and_copy(self):
nd = statistics.NormalDist(37.5, 5.625)
nd = self.module.NormalDist(37.5, 5.625)
nd1 = copy.copy(nd)
self.assertEqual(nd, nd1)
nd2 = copy.deepcopy(nd)
@ -2682,14 +2700,36 @@ def test_pickle_and_copy(self):
self.assertEqual(nd, nd3)
def test_hashability(self):
ND = statistics.NormalDist
ND = self.module.NormalDist
s = {ND(100, 15), ND(100.0, 15.0), ND(100, 10), ND(95, 15), ND(100, 15)}
self.assertEqual(len(s), 3)
def test_repr(self):
nd = statistics.NormalDist(37.5, 5.625)
nd = self.module.NormalDist(37.5, 5.625)
self.assertEqual(repr(nd), 'NormalDist(mu=37.5, sigma=5.625)')
# Swapping the sys.modules['statistics'] is to solving the
# _pickle.PicklingError:
# Can't pickle <class 'statistics.NormalDist'>:
# it's not the same object as statistics.NormalDist
class TestNormalDistPython(unittest.TestCase, TestNormalDist):
module = py_statistics
def setUp(self):
sys.modules['statistics'] = self.module
def tearDown(self):
sys.modules['statistics'] = statistics
@unittest.skipUnless(c_statistics, 'requires _statistics')
class TestNormalDistC(unittest.TestCase, TestNormalDist):
module = c_statistics
def setUp(self):
sys.modules['statistics'] = self.module
def tearDown(self):
sys.modules['statistics'] = statistics
# === Run tests ===

View file

@ -0,0 +1,2 @@
Update test_statistics.py to verify that the statistics module works well
for both C and Python implementations. Patch by Dong-hee Na