cpython/Lib/test/test_itertools.py

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import unittest
from test import test_support
from itertools import *
import sys
class TestBasicOps(unittest.TestCase):
def test_chain(self):
self.assertEqual(list(chain('abc', 'def')), list('abcdef'))
def test_count(self):
self.assertEqual(zip('abc',count()), [('a', 0), ('b', 1), ('c', 2)])
self.assertEqual(zip('abc',count(3)), [('a', 3), ('b', 4), ('c', 5)])
self.assertRaises(TypeError, count, 2, 3)
def test_cycle(self):
self.assertEqual(list(islice(cycle('abc'),10)), list('abcabcabca'))
self.assertEqual(list(cycle('')), [])
def test_ifilter(self):
def isEven(x):
return x%2==0
self.assertEqual(list(ifilter(isEven, range(6))), [0,2,4])
self.assertEqual(list(ifilter(None, [0,1,0,2,0])), [1,2])
self.assertRaises(TypeError, ifilter)
self.assertRaises(TypeError, ifilter, 3)
self.assertRaises(TypeError, ifilter, isEven, 3)
def test_ifilterfalse(self):
def isEven(x):
return x%2==0
self.assertEqual(list(ifilterfalse(isEven, range(6))), [1,3,5])
self.assertEqual(list(ifilterfalse(None, [0,1,0,2,0])), [0,0,0])
self.assertRaises(TypeError, ifilterfalse)
self.assertRaises(TypeError, ifilterfalse, 3)
self.assertRaises(TypeError, ifilterfalse, isEven, 3)
def test_izip(self):
ans = [(x,y) for x, y in izip('abc',count())]
self.assertEqual(ans, [('a', 0), ('b', 1), ('c', 2)])
self.assertRaises(TypeError, izip)
def test_repeat(self):
self.assertEqual(zip(xrange(3),repeat('a')),
[(0, 'a'), (1, 'a'), (2, 'a')])
self.assertEqual(list(repeat('a', 3)), ['a', 'a', 'a'])
self.assertRaises(TypeError, repeat)
def test_imap(self):
import operator
self.assertEqual(list(imap(operator.pow, range(3), range(1,7))),
[0**1, 1**2, 2**3])
self.assertEqual(list(imap(None, 'abc', range(5))),
[('a',0),('b',1),('c',2)])
self.assertRaises(TypeError, imap)
self.assertRaises(TypeError, imap, operator.neg)
def test_starmap(self):
import operator
self.assertEqual(list(starmap(operator.pow, zip(range(3), range(1,7)))),
[0**1, 1**2, 2**3])
self.assertRaises(TypeError, list, starmap(operator.pow, [[4,5]]))
def test_islice(self):
for args in [ # islice(args) should agree with range(args)
(10, 20, 3),
(10, 3, 20),
(10, 20),
(10, 3),
(20,)
]:
self.assertEqual(list(islice(xrange(100), *args)), range(*args))
for args, tgtargs in [ # Stop when seqn is exhausted
((10, 110, 3), ((10, 100, 3))),
((10, 110), ((10, 100))),
((110,), (100,))
]:
self.assertEqual(list(islice(xrange(100), *args)), range(*tgtargs))
self.assertRaises(TypeError, islice, xrange(10))
self.assertRaises(TypeError, islice, xrange(10), 1, 2, 3, 4)
self.assertRaises(ValueError, islice, xrange(10), -5, 10, 1)
self.assertRaises(ValueError, islice, xrange(10), 1, -5, -1)
self.assertRaises(ValueError, islice, xrange(10), 1, 10, -1)
self.assertRaises(ValueError, islice, xrange(10), 1, 10, 0)
self.assertEqual(len(list(islice(count(), 1, 10, sys.maxint))), 1)
def test_takewhile(self):
data = [1, 3, 5, 20, 2, 4, 6, 8]
underten = lambda x: x<10
self.assertEqual(list(takewhile(underten, data)), [1, 3, 5])
def test_dropwhile(self):
data = [1, 3, 5, 20, 2, 4, 6, 8]
underten = lambda x: x<10
self.assertEqual(list(dropwhile(underten, data)), [20, 2, 4, 6, 8])
libreftest = """ Doctest for examples in the library reference, libitertools.tex
>>> amounts = [120.15, 764.05, 823.14]
>>> for checknum, amount in izip(count(1200), amounts):
... print 'Check %d is for $%.2f' % (checknum, amount)
...
Check 1200 is for $120.15
Check 1201 is for $764.05
Check 1202 is for $823.14
>>> import operator
>>> import operator
>>> for cube in imap(operator.pow, xrange(1,4), repeat(3)):
... print cube
...
1
8
27
>>> reportlines = ['EuroPython', 'Roster', '', 'alex', '', 'laura', '', 'martin', '', 'walter', '', 'samuele']
>>> for name in islice(reportlines, 3, len(reportlines), 2):
... print name.title()
...
Alex
Laura
Martin
Walter
Samuele
>>> def enumerate(iterable):
... return izip(count(), iterable)
>>> def tabulate(function):
... "Return function(0), function(1), ..."
... return imap(function, count())
>>> def iteritems(mapping):
... return izip(mapping.iterkeys(), mapping.itervalues())
>>> def nth(iterable, n):
... "Returns the nth item"
... return list(islice(iterable, n, n+1))
>>> def all(pred, seq):
... "Returns True if pred(x) is True for every element in the iterable"
... return not nth(ifilterfalse(pred, seq), 0)
>>> def some(pred, seq):
... "Returns True if pred(x) is True at least one element in the iterable"
... return bool(nth(ifilter(pred, seq), 0))
>>> def no(pred, seq):
... "Returns True if pred(x) is False for every element in the iterable"
... return not nth(ifilter(pred, seq), 0)
>>> def pairwise(seq):
... "s -> (s0,s1), (s1,s2), (s2, s3), ..."
... return izip(seq, islice(seq,1,len(seq)))
"""
__test__ = {'libreftest' : libreftest}
def test_main(verbose=None):
import test_itertools
suite = unittest.TestSuite()
for testclass in (TestBasicOps,
):
suite.addTest(unittest.makeSuite(testclass))
test_support.run_suite(suite)
test_support.run_doctest(test_itertools, verbose)
# verify reference counting
import sys
if verbose and hasattr(sys, "gettotalrefcount"):
counts = []
for i in xrange(5):
test_support.run_suite(suite)
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counts.append(sys.gettotalrefcount()-i)
print counts
if __name__ == "__main__":
test_main(verbose=True)