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from test import support
import random
import unittest
from functools import cmp_to_key
verbose = support.verbose
nerrors = 0
def check(tag, expected, raw, compare=None):
global nerrors
if verbose:
print(" checking", tag)
orig = raw[:] # save input in case of error
if compare:
raw.sort(key=cmp_to_key(compare))
else:
raw.sort()
if len(expected) != len(raw):
print("error in", tag)
print("length mismatch;", len(expected), len(raw))
print(expected)
print(orig)
print(raw)
nerrors += 1
return
for i, good in enumerate(expected):
maybe = raw[i]
if good is not maybe:
print("error in", tag)
print("out of order at index", i, good, maybe)
print(expected)
print(orig)
print(raw)
nerrors += 1
return
class TestBase(unittest.TestCase):
def testStressfully(self):
# Try a variety of sizes at and around powers of 2, and at powers of 10.
sizes = [0]
for power in range(1, 10):
n = 2 ** power
sizes.extend(range(n-1, n+2))
sizes.extend([10, 100, 1000])
class Complains(object):
maybe_complain = True
def __init__(self, i):
self.i = i
def __lt__(self, other):
if Complains.maybe_complain and random.random() < 0.001:
if verbose:
print(" complaining at", self, other)
raise RuntimeError
return self.i < other.i
def __repr__(self):
return "Complains(%d)" % self.i
class Stable(object):
def __init__(self, key, i):
self.key = key
self.index = i
def __lt__(self, other):
return self.key < other.key
def __repr__(self):
return "Stable(%d, %d)" % (self.key, self.index)
for n in sizes:
x = list(range(n))
if verbose:
print("Testing size", n)
s = x[:]
check("identity", x, s)
s = x[:]
s.reverse()
check("reversed", x, s)
s = x[:]
random.shuffle(s)
check("random permutation", x, s)
y = x[:]
y.reverse()
s = x[:]
check("reversed via function", y, s, lambda a, b: (b>a)-(b<a))
if verbose:
print(" Checking against an insane comparison function.")
print(" If the implementation isn't careful, this may segfault.")
s = x[:]
s.sort(key=cmp_to_key(lambda a, b: int(random.random() * 3) - 1))
check("an insane function left some permutation", x, s)
if len(x) >= 2:
def bad_key(x):
raise RuntimeError
s = x[:]
self.assertRaises(RuntimeError, s.sort, key=bad_key)
x = [Complains(i) for i in x]
s = x[:]
random.shuffle(s)
Complains.maybe_complain = True
it_complained = False
try:
s.sort()
except RuntimeError:
it_complained = True
if it_complained:
Complains.maybe_complain = False
check("exception during sort left some permutation", x, s)
s = [Stable(random.randrange(10), i) for i in range(n)]
augmented = [(e, e.index) for e in s]
augmented.sort() # forced stable because ties broken by index
x = [e for e, i in augmented] # a stable sort of s
check("stability", x, s)
#==============================================================================
class TestBugs(unittest.TestCase):
def test_bug453523(self):
# bug 453523 -- list.sort() crasher.
# If this fails, the most likely outcome is a core dump.
# Mutations during a list sort should raise a ValueError.
class C:
def __lt__(self, other):
if L and random.random() < 0.75:
L.pop()
else:
L.append(3)
return random.random() < 0.5
L = [C() for i in range(50)]
self.assertRaises(ValueError, L.sort)
def test_undetected_mutation(self):
# Python 2.4a1 did not always detect mutation
memorywaster = []
for i in range(20):
def mutating_cmp(x, y):
L.append(3)
L.pop()
return (x > y) - (x < y)
L = [1,2]
self.assertRaises(ValueError, L.sort, key=cmp_to_key(mutating_cmp))
def mutating_cmp(x, y):
L.append(3)
del L[:]
return (x > y) - (x < y)
self.assertRaises(ValueError, L.sort, key=cmp_to_key(mutating_cmp))
memorywaster = [memorywaster]
#==============================================================================
class TestDecorateSortUndecorate(unittest.TestCase):
def test_decorated(self):
data = 'The quick Brown fox Jumped over The lazy Dog'.split()
copy = data[:]
random.shuffle(data)
data.sort(key=str.lower)
def my_cmp(x, y):
xlower, ylower = x.lower(), y.lower()
return (xlower > ylower) - (xlower < ylower)
copy.sort(key=cmp_to_key(my_cmp))
def test_baddecorator(self):
data = 'The quick Brown fox Jumped over The lazy Dog'.split()
self.assertRaises(TypeError, data.sort, key=lambda x,y: 0)
def test_stability(self):
data = [(random.randrange(100), i) for i in range(200)]
copy = data[:]
data.sort(key=lambda t: t[0]) # sort on the random first field
copy.sort() # sort using both fields
self.assertEqual(data, copy) # should get the same result
def test_key_with_exception(self):
# Verify that the wrapper has been removed
data = list(range(-2, 2))
dup = data[:]
self.assertRaises(ZeroDivisionError, data.sort, key=lambda x: 1/x)
self.assertEqual(data, dup)
def test_key_with_mutation(self):
data = list(range(10))
def k(x):
del data[:]
data[:] = range(20)
return x
self.assertRaises(ValueError, data.sort, key=k)
def test_key_with_mutating_del(self):
data = list(range(10))
class SortKiller(object):
def __init__(self, x):
pass
def __del__(self):
del data[:]
data[:] = range(20)
def __lt__(self, other):
return id(self) < id(other)
self.assertRaises(ValueError, data.sort, key=SortKiller)
def test_key_with_mutating_del_and_exception(self):
data = list(range(10))
## dup = data[:]
class SortKiller(object):
def __init__(self, x):
if x > 2:
raise RuntimeError
def __del__(self):
del data[:]
data[:] = list(range(20))
self.assertRaises(RuntimeError, data.sort, key=SortKiller)
## major honking subtlety: we *can't* do:
##
## self.assertEqual(data, dup)
##
## because there is a reference to a SortKiller in the
## traceback and by the time it dies we're outside the call to
## .sort() and so the list protection gimmicks are out of
## date (this cost some brain cells to figure out...).
def test_reverse(self):
data = list(range(100))
random.shuffle(data)
data.sort(reverse=True)
self.assertEqual(data, list(range(99,-1,-1)))
def test_reverse_stability(self):
data = [(random.randrange(100), i) for i in range(200)]
copy1 = data[:]
copy2 = data[:]
def my_cmp(x, y):
x0, y0 = x[0], y[0]
return (x0 > y0) - (x0 < y0)
def my_cmp_reversed(x, y):
x0, y0 = x[0], y[0]
return (y0 > x0) - (y0 < x0)
data.sort(key=cmp_to_key(my_cmp), reverse=True)
copy1.sort(key=cmp_to_key(my_cmp_reversed))
self.assertEqual(data, copy1)
copy2.sort(key=lambda x: x[0], reverse=True)
self.assertEqual(data, copy2)
#==============================================================================
if __name__ == "__main__":
unittest.main()
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