Initial commit of OpenSPARC T2 architecture model.

[OpenSPARC-T2-SAM] / sam-t2 / devtools / amd64 / lib / python2.4 / test / test_itertools.py

import unittest
from test import test_support
from itertools import *
from weakref import proxy
import sys
import operator
import random

def onearg(x):
   'Test function of one argument'
   return 2*x

def errfunc(*args):
   'Test function that raises an error'
   raise ValueError

def gen3():
   'Non-restartable source sequence'
   for i in (0, 1, 2):
       yield i

def isEven(x):
   'Test predicate'
   return x%2==0

def isOdd(x):
   'Test predicate'
   return x%2==1

class StopNow:
   'Class emulating an empty iterable.'
   def __iter__(self):
       return self
   def next(self):
       raise StopIteration

def take(n, seq):
   'Convenience function for partially consuming a long of infinite iterable'
   return list(islice(seq, n))

class TestBasicOps(unittest.TestCase):
   def test_chain(self):
       self.assertEqual(list(chain('abc', 'def')), list('abcdef'))
       self.assertEqual(list(chain('abc')), list('abc'))
       self.assertEqual(list(chain('')), [])
       self.assertEqual(take(4, chain('abc', 'def')), list('abcd'))
       self.assertRaises(TypeError, chain, 2, 3)

   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.assertEqual(take(2, zip('abc',count(3))), [('a', 3), ('b', 4)])
       self.assertRaises(TypeError, count, 2, 3)
       self.assertRaises(TypeError, count, 'a')
       c = count(sys.maxint-2)   # verify that rollover doesn't crash
       c.next(); c.next(); c.next(); c.next(); c.next()
       c = count(3)
       self.assertEqual(repr(c), 'count(3)')
       c.next()
       self.assertEqual(repr(c), 'count(4)')

   def test_cycle(self):
       self.assertEqual(take(10, cycle('abc')), list('abcabcabca'))
       self.assertEqual(list(cycle('')), [])
       self.assertRaises(TypeError, cycle)
       self.assertRaises(TypeError, cycle, 5)
       self.assertEqual(list(islice(cycle(gen3()),10)), [0,1,2,0,1,2,0,1,2,0])

   def test_groupby(self):
       # Check whether it accepts arguments correctly
       self.assertEqual([], list(groupby([])))
       self.assertEqual([], list(groupby([], key=id)))
       self.assertRaises(TypeError, list, groupby('abc', []))
       self.assertRaises(TypeError, groupby, None)
       self.assertRaises(TypeError, groupby, 'abc', lambda x:x, 10)

       # Check normal input
       s = [(0, 10, 20), (0, 11,21), (0,12,21), (1,13,21), (1,14,22),
            (2,15,22), (3,16,23), (3,17,23)]
       dup = []
       for k, g in groupby(s, lambda r:r[0]):
           for elem in g:
               self.assertEqual(k, elem[0])
               dup.append(elem)
       self.assertEqual(s, dup)

       # Check nested case
       dup = []
       for k, g in groupby(s, lambda r:r[0]):
           for ik, ig in groupby(g, lambda r:r[2]):
               for elem in ig:
                   self.assertEqual(k, elem[0])
                   self.assertEqual(ik, elem[2])
                   dup.append(elem)
       self.assertEqual(s, dup)

       # Check case where inner iterator is not used
       keys = [k for k, g in groupby(s, lambda r:r[0])]
       expectedkeys = set([r[0] for r in s])
       self.assertEqual(set(keys), expectedkeys)
       self.assertEqual(len(keys), len(expectedkeys))

       # Exercise pipes and filters style
       s = 'abracadabra'
       # sort s | uniq
       r = [k for k, g in groupby(sorted(s))]
       self.assertEqual(r, ['a', 'b', 'c', 'd', 'r'])
       # sort s | uniq -d
       r = [k for k, g in groupby(sorted(s)) if list(islice(g,1,2))]
       self.assertEqual(r, ['a', 'b', 'r'])
       # sort s | uniq -c
       r = [(len(list(g)), k) for k, g in groupby(sorted(s))]
       self.assertEqual(r, [(5, 'a'), (2, 'b'), (1, 'c'), (1, 'd'), (2, 'r')])
       # sort s | uniq -c | sort -rn | head -3
       r = sorted([(len(list(g)) , k) for k, g in groupby(sorted(s))], reverse=True)[:3]
       self.assertEqual(r, [(5, 'a'), (2, 'r'), (2, 'b')])

       # iter.next failure
       class ExpectedError(Exception):
           pass
       def delayed_raise(n=0):
           for i in range(n):
               yield 'yo'
           raise ExpectedError
       def gulp(iterable, keyp=None, func=list):
           return [func(g) for k, g in groupby(iterable, keyp)]

       # iter.next failure on outer object
       self.assertRaises(ExpectedError, gulp, delayed_raise(0))
       # iter.next failure on inner object
       self.assertRaises(ExpectedError, gulp, delayed_raise(1))

       # __cmp__ failure
       class DummyCmp:
           def __cmp__(self, dst):
               raise ExpectedError
       s = [DummyCmp(), DummyCmp(), None]

       # __cmp__ failure on outer object
       self.assertRaises(ExpectedError, gulp, s, func=id)
       # __cmp__ failure on inner object
       self.assertRaises(ExpectedError, gulp, s)

       # keyfunc failure
       def keyfunc(obj):
           if keyfunc.skip > 0:
               keyfunc.skip -= 1
               return obj
           else:
               raise ExpectedError

       # keyfunc failure on outer object
       keyfunc.skip = 0
       self.assertRaises(ExpectedError, gulp, [None], keyfunc)
       keyfunc.skip = 1
       self.assertRaises(ExpectedError, gulp, [None, None], keyfunc)

   def test_ifilter(self):
       self.assertEqual(list(ifilter(isEven, range(6))), [0,2,4])
       self.assertEqual(list(ifilter(None, [0,1,0,2,0])), [1,2])
       self.assertEqual(take(4, ifilter(isEven, count())), [0,2,4,6])
       self.assertRaises(TypeError, ifilter)
       self.assertRaises(TypeError, ifilter, lambda x:x)
       self.assertRaises(TypeError, ifilter, lambda x:x, range(6), 7)
       self.assertRaises(TypeError, ifilter, isEven, 3)
       self.assertRaises(TypeError, ifilter(range(6), range(6)).next)

   def test_ifilterfalse(self):
       self.assertEqual(list(ifilterfalse(isEven, range(6))), [1,3,5])
       self.assertEqual(list(ifilterfalse(None, [0,1,0,2,0])), [0,0,0])
       self.assertEqual(take(4, ifilterfalse(isEven, count())), [1,3,5,7])
       self.assertRaises(TypeError, ifilterfalse)
       self.assertRaises(TypeError, ifilterfalse, lambda x:x)
       self.assertRaises(TypeError, ifilterfalse, lambda x:x, range(6), 7)
       self.assertRaises(TypeError, ifilterfalse, isEven, 3)
       self.assertRaises(TypeError, ifilterfalse(range(6), range(6)).next)

   def test_izip(self):
       ans = [(x,y) for x, y in izip('abc',count())]
       self.assertEqual(ans, [('a', 0), ('b', 1), ('c', 2)])
       self.assertEqual(list(izip('abc', range(6))), zip('abc', range(6)))
       self.assertEqual(list(izip('abcdef', range(3))), zip('abcdef', range(3)))
       self.assertEqual(take(3,izip('abcdef', count())), zip('abcdef', range(3)))
       self.assertEqual(list(izip('abcdef')), zip('abcdef'))
       self.assertEqual(list(izip()), zip())
       self.assertRaises(TypeError, izip, 3)
       self.assertRaises(TypeError, izip, range(3), 3)
       # Check tuple re-use (implementation detail)
       self.assertEqual([tuple(list(pair)) for pair in izip('abc', 'def')],
                        zip('abc', 'def'))
       self.assertEqual([pair for pair in izip('abc', 'def')],
                        zip('abc', 'def'))
       ids = map(id, izip('abc', 'def'))
       self.assertEqual(min(ids), max(ids))
       ids = map(id, list(izip('abc', 'def')))
       self.assertEqual(len(dict.fromkeys(ids)), len(ids))

   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.assertEqual(take(3, repeat('a')), ['a', 'a', 'a'])
       self.assertEqual(list(repeat('a', 0)), [])
       self.assertEqual(list(repeat('a', -3)), [])
       self.assertRaises(TypeError, repeat)
       self.assertRaises(TypeError, repeat, None, 3, 4)
       self.assertRaises(TypeError, repeat, None, 'a')
       r = repeat(1+0j)
       self.assertEqual(repr(r), 'repeat((1+0j))')
       r = repeat(1+0j, 5)
       self.assertEqual(repr(r), 'repeat((1+0j), 5)')
       list(r)
       self.assertEqual(repr(r), 'repeat((1+0j), 0)')

   def test_imap(self):
       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.assertEqual(list(imap(None, 'abc', count())),
                        [('a',0),('b',1),('c',2)])
       self.assertEqual(take(2,imap(None, 'abc', count())),
                        [('a',0),('b',1)])
       self.assertEqual(list(imap(operator.pow, [])), [])
       self.assertRaises(TypeError, imap)
       self.assertRaises(TypeError, imap, operator.neg)
       self.assertRaises(TypeError, imap(10, range(5)).next)
       self.assertRaises(ValueError, imap(errfunc, [4], [5]).next)
       self.assertRaises(TypeError, imap(onearg, [4], [5]).next)

   def test_starmap(self):
       self.assertEqual(list(starmap(operator.pow, zip(range(3), range(1,7)))),
                        [0**1, 1**2, 2**3])
       self.assertEqual(take(3, starmap(operator.pow, izip(count(), count(1)))),
                        [0**1, 1**2, 2**3])
       self.assertEqual(list(starmap(operator.pow, [])), [])
       self.assertRaises(TypeError, list, starmap(operator.pow, [[4,5]]))
       self.assertRaises(TypeError, starmap)
       self.assertRaises(TypeError, starmap, operator.pow, [(4,5)], 'extra')
       self.assertRaises(TypeError, starmap(10, [(4,5)]).next)
       self.assertRaises(ValueError, starmap(errfunc, [(4,5)]).next)
       self.assertRaises(TypeError, starmap(onearg, [(4,5)]).next)

   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))

       # Test stop=None
       self.assertEqual(list(islice(xrange(10), None)), range(10))
       self.assertEqual(list(islice(xrange(10), 2, None)), range(2, 10))
       self.assertEqual(list(islice(xrange(10), 1, None, 2)), range(1, 10, 2))

       # Test invalid arguments
       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.assertRaises(ValueError, islice, xrange(10), 'a')
       self.assertRaises(ValueError, islice, xrange(10), 'a', 1)
       self.assertRaises(ValueError, islice, xrange(10), 1, 'a')
       self.assertRaises(ValueError, islice, xrange(10), 'a', 1, 1)
       self.assertRaises(ValueError, islice, xrange(10), 1, 'a', 1)
       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])
       self.assertEqual(list(takewhile(underten, [])), [])
       self.assertRaises(TypeError, takewhile)
       self.assertRaises(TypeError, takewhile, operator.pow)
       self.assertRaises(TypeError, takewhile, operator.pow, [(4,5)], 'extra')
       self.assertRaises(TypeError, takewhile(10, [(4,5)]).next)
       self.assertRaises(ValueError, takewhile(errfunc, [(4,5)]).next)
       t = takewhile(bool, [1, 1, 1, 0, 0, 0])
       self.assertEqual(list(t), [1, 1, 1])
       self.assertRaises(StopIteration, t.next)

   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])
       self.assertEqual(list(dropwhile(underten, [])), [])
       self.assertRaises(TypeError, dropwhile)
       self.assertRaises(TypeError, dropwhile, operator.pow)
       self.assertRaises(TypeError, dropwhile, operator.pow, [(4,5)], 'extra')
       self.assertRaises(TypeError, dropwhile(10, [(4,5)]).next)
       self.assertRaises(ValueError, dropwhile(errfunc, [(4,5)]).next)

   def test_tee(self):
       n = 200
       def irange(n):
           for i in xrange(n):
               yield i

       a, b = tee([])        # test empty iterator
       self.assertEqual(list(a), [])
       self.assertEqual(list(b), [])

       a, b = tee(irange(n)) # test 100% interleaved
       self.assertEqual(zip(a,b), zip(range(n),range(n)))

       a, b = tee(irange(n)) # test 0% interleaved
       self.assertEqual(list(a), range(n))
       self.assertEqual(list(b), range(n))

       a, b = tee(irange(n)) # test dealloc of leading iterator
       for i in xrange(100):
           self.assertEqual(a.next(), i)
       del a
       self.assertEqual(list(b), range(n))

       a, b = tee(irange(n)) # test dealloc of trailing iterator
       for i in xrange(100):
           self.assertEqual(a.next(), i)
       del b
       self.assertEqual(list(a), range(100, n))

       for j in xrange(5):   # test randomly interleaved
           order = [0]*n + [1]*n
           random.shuffle(order)
           lists = ([], [])
           its = tee(irange(n))
           for i in order:
               value = its[i].next()
               lists[i].append(value)
           self.assertEqual(lists[0], range(n))
           self.assertEqual(lists[1], range(n))

       # test argument format checking
       self.assertRaises(TypeError, tee)
       self.assertRaises(TypeError, tee, 3)
       self.assertRaises(TypeError, tee, [1,2], 'x')
       self.assertRaises(TypeError, tee, [1,2], 3, 'x')

       # tee object should be instantiable
       a, b = tee('abc')
       c = type(a)('def')
       self.assertEqual(list(c), list('def'))

       # test long-lagged and multi-way split
       a, b, c = tee(xrange(2000), 3)
       for i in xrange(100):
           self.assertEqual(a.next(), i)
       self.assertEqual(list(b), range(2000))
       self.assertEqual([c.next(), c.next()], range(2))
       self.assertEqual(list(a), range(100,2000))
       self.assertEqual(list(c), range(2,2000))

       # test values of n
       self.assertRaises(TypeError, tee, 'abc', 'invalid')
       for n in xrange(5):
           result = tee('abc', n)
           self.assertEqual(type(result), tuple)
           self.assertEqual(len(result), n)
           self.assertEqual(map(list, result), [list('abc')]*n)

       # tee pass-through to copyable iterator
       a, b = tee('abc')
       c, d = tee(a)
       self.assert_(a is c)

       # test tee_new
       t1, t2 = tee('abc')
       tnew = type(t1)
       self.assertRaises(TypeError, tnew)
       self.assertRaises(TypeError, tnew, 10)
       t3 = tnew(t1)
       self.assert_(list(t1) == list(t2) == list(t3) == list('abc'))

       # test that tee objects are weak referencable
       a, b = tee(xrange(10))
       p = proxy(a)
       self.assertEqual(getattr(p, '__class__'), type(b))
       del a
       self.assertRaises(ReferenceError, getattr, p, '__class__')

   def test_StopIteration(self):
       self.assertRaises(StopIteration, izip().next)

       for f in (chain, cycle, izip, groupby):
           self.assertRaises(StopIteration, f([]).next)
           self.assertRaises(StopIteration, f(StopNow()).next)

       self.assertRaises(StopIteration, islice([], None).next)
       self.assertRaises(StopIteration, islice(StopNow(), None).next)

       p, q = tee([])
       self.assertRaises(StopIteration, p.next)
       self.assertRaises(StopIteration, q.next)
       p, q = tee(StopNow())
       self.assertRaises(StopIteration, p.next)
       self.assertRaises(StopIteration, q.next)

       self.assertRaises(StopIteration, repeat(None, 0).next)

       for f in (ifilter, ifilterfalse, imap, takewhile, dropwhile, starmap):
           self.assertRaises(StopIteration, f(lambda x:x, []).next)
           self.assertRaises(StopIteration, f(lambda x:x, StopNow()).next)

class TestGC(unittest.TestCase):

   def makecycle(self, iterator, container):
       container.append(iterator)
       iterator.next()
       del container, iterator

   def test_chain(self):
       a = []
       self.makecycle(chain(a), a)

   def test_cycle(self):
       a = []
       self.makecycle(cycle([a]*2), a)

   def test_dropwhile(self):
       a = []
       self.makecycle(dropwhile(bool, [0, a, a]), a)

   def test_groupby(self):
       a = []
       self.makecycle(groupby([a]*2, lambda x:x), a)

   def test_ifilter(self):
       a = []
       self.makecycle(ifilter(lambda x:True, [a]*2), a)

   def test_ifilterfalse(self):
       a = []
       self.makecycle(ifilterfalse(lambda x:False, a), a)

   def test_izip(self):
       a = []
       self.makecycle(izip([a]*2, [a]*3), a)

   def test_imap(self):
       a = []
       self.makecycle(imap(lambda x:x, [a]*2), a)

   def test_islice(self):
       a = []
       self.makecycle(islice([a]*2, None), a)

   def test_repeat(self):
       a = []
       self.makecycle(repeat(a), a)

   def test_starmap(self):
       a = []
       self.makecycle(starmap(lambda *t: t, [(a,a)]*2), a)

   def test_takewhile(self):
       a = []
       self.makecycle(takewhile(bool, [1, 0, a, a]), a)

def R(seqn):
   'Regular generator'
   for i in seqn:
       yield i

class G:
   'Sequence using __getitem__'
   def __init__(self, seqn):
       self.seqn = seqn
   def __getitem__(self, i):
       return self.seqn[i]

class I:
   'Sequence using iterator protocol'
   def __init__(self, seqn):
       self.seqn = seqn
       self.i = 0
   def __iter__(self):
       return self
   def next(self):
       if self.i >= len(self.seqn): raise StopIteration
       v = self.seqn[self.i]
       self.i += 1
       return v

class Ig:
   'Sequence using iterator protocol defined with a generator'
   def __init__(self, seqn):
       self.seqn = seqn
       self.i = 0
   def __iter__(self):
       for val in self.seqn:
           yield val

class X:
   'Missing __getitem__ and __iter__'
   def __init__(self, seqn):
       self.seqn = seqn
       self.i = 0
   def next(self):
       if self.i >= len(self.seqn): raise StopIteration
       v = self.seqn[self.i]
       self.i += 1
       return v

class N:
   'Iterator missing next()'
   def __init__(self, seqn):
       self.seqn = seqn
       self.i = 0
   def __iter__(self):
       return self

class E:
   'Test propagation of exceptions'
   def __init__(self, seqn):
       self.seqn = seqn
       self.i = 0
   def __iter__(self):
       return self
   def next(self):
       3 // 0

class S:
   'Test immediate stop'
   def __init__(self, seqn):
       pass
   def __iter__(self):
       return self
   def next(self):
       raise StopIteration

def L(seqn):
   'Test multiple tiers of iterators'
   return chain(imap(lambda x:x, R(Ig(G(seqn)))))


class TestVariousIteratorArgs(unittest.TestCase):

   def test_chain(self):
       for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual(list(chain(g(s))), list(g(s)))
               self.assertEqual(list(chain(g(s), g(s))), list(g(s))+list(g(s)))
           self.assertRaises(TypeError, chain, X(s))
           self.assertRaises(TypeError, list, chain(N(s)))
           self.assertRaises(ZeroDivisionError, list, chain(E(s)))

   def test_cycle(self):
       for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               tgtlen = len(s) * 3
               expected = list(g(s))*3
               actual = list(islice(cycle(g(s)), tgtlen))
               self.assertEqual(actual, expected)
           self.assertRaises(TypeError, cycle, X(s))
           self.assertRaises(TypeError, list, cycle(N(s)))
           self.assertRaises(ZeroDivisionError, list, cycle(E(s)))

   def test_groupby(self):
       for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual([k for k, sb in groupby(g(s))], list(g(s)))
           self.assertRaises(TypeError, groupby, X(s))
           self.assertRaises(TypeError, list, groupby(N(s)))
           self.assertRaises(ZeroDivisionError, list, groupby(E(s)))

   def test_ifilter(self):
       for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual(list(ifilter(isEven, g(s))), filter(isEven, g(s)))
           self.assertRaises(TypeError, ifilter, isEven, X(s))
           self.assertRaises(TypeError, list, ifilter(isEven, N(s)))
           self.assertRaises(ZeroDivisionError, list, ifilter(isEven, E(s)))

   def test_ifilterfalse(self):
       for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual(list(ifilterfalse(isEven, g(s))), filter(isOdd, g(s)))
           self.assertRaises(TypeError, ifilterfalse, isEven, X(s))
           self.assertRaises(TypeError, list, ifilterfalse(isEven, N(s)))
           self.assertRaises(ZeroDivisionError, list, ifilterfalse(isEven, E(s)))

   def test_izip(self):
       for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual(list(izip(g(s))), zip(g(s)))
               self.assertEqual(list(izip(g(s), g(s))), zip(g(s), g(s)))
           self.assertRaises(TypeError, izip, X(s))
           self.assertRaises(TypeError, list, izip(N(s)))
           self.assertRaises(ZeroDivisionError, list, izip(E(s)))

   def test_imap(self):
       for s in (range(10), range(0), range(100), (7,11), xrange(20,50,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual(list(imap(onearg, g(s))), map(onearg, g(s)))
               self.assertEqual(list(imap(operator.pow, g(s), g(s))), map(operator.pow, g(s), g(s)))
           self.assertRaises(TypeError, imap, onearg, X(s))
           self.assertRaises(TypeError, list, imap(onearg, N(s)))
           self.assertRaises(ZeroDivisionError, list, imap(onearg, E(s)))

   def test_islice(self):
       for s in ("12345", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               self.assertEqual(list(islice(g(s),1,None,2)), list(g(s))[1::2])
           self.assertRaises(TypeError, islice, X(s), 10)
           self.assertRaises(TypeError, list, islice(N(s), 10))
           self.assertRaises(ZeroDivisionError, list, islice(E(s), 10))

   def test_starmap(self):
       for s in (range(10), range(0), range(100), (7,11), xrange(20,50,5)):
           for g in (G, I, Ig, S, L, R):
               ss = zip(s, s)
               self.assertEqual(list(starmap(operator.pow, g(ss))), map(operator.pow, g(s), g(s)))
           self.assertRaises(TypeError, starmap, operator.pow, X(ss))
           self.assertRaises(TypeError, list, starmap(operator.pow, N(ss)))
           self.assertRaises(ZeroDivisionError, list, starmap(operator.pow, E(ss)))

   def test_takewhile(self):
       for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               tgt = []
               for elem in g(s):
                   if not isEven(elem): break
                   tgt.append(elem)
               self.assertEqual(list(takewhile(isEven, g(s))), tgt)
           self.assertRaises(TypeError, takewhile, isEven, X(s))
           self.assertRaises(TypeError, list, takewhile(isEven, N(s)))
           self.assertRaises(ZeroDivisionError, list, takewhile(isEven, E(s)))

   def test_dropwhile(self):
       for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               tgt = []
               for elem in g(s):
                   if not tgt and isOdd(elem): continue
                   tgt.append(elem)
               self.assertEqual(list(dropwhile(isOdd, g(s))), tgt)
           self.assertRaises(TypeError, dropwhile, isOdd, X(s))
           self.assertRaises(TypeError, list, dropwhile(isOdd, N(s)))
           self.assertRaises(ZeroDivisionError, list, dropwhile(isOdd, E(s)))

   def test_tee(self):
       for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)):
           for g in (G, I, Ig, S, L, R):
               it1, it2 = tee(g(s))
               self.assertEqual(list(it1), list(g(s)))
               self.assertEqual(list(it2), list(g(s)))
           self.assertRaises(TypeError, tee, X(s))
           self.assertRaises(TypeError, list, tee(N(s))[0])
           self.assertRaises(ZeroDivisionError, list, tee(E(s))[0])

class LengthTransparency(unittest.TestCase):

   def test_repeat(self):
       self.assertEqual(len(repeat(None, 50)), 50)
       self.assertRaises(TypeError, len, repeat(None))

class RegressionTests(unittest.TestCase):

   def test_sf_793826(self):
       # Fix Armin Rigo's successful efforts to wreak havoc

       def mutatingtuple(tuple1, f, tuple2):
           # this builds a tuple t which is a copy of tuple1,
           # then calls f(t), then mutates t to be equal to tuple2
           # (needs len(tuple1) == len(tuple2)).
           def g(value, first=[1]):
               if first:
                   del first[:]
                   f(z.next())
               return value
           items = list(tuple2)
           items[1:1] = list(tuple1)
           gen = imap(g, items)
           z = izip(*[gen]*len(tuple1))
           z.next()

       def f(t):
           global T
           T = t
           first[:] = list(T)

       first = []
       mutatingtuple((1,2,3), f, (4,5,6))
       second = list(T)
       self.assertEqual(first, second)


   def test_sf_950057(self):
       # Make sure that chain() and cycle() catch exceptions immediately
       # rather than when shifting between input sources

       def gen1():
           hist.append(0)
           yield 1
           hist.append(1)
           raise AssertionError
           hist.append(2)

       def gen2(x):
           hist.append(3)
           yield 2
           hist.append(4)
           if x:
               raise StopIteration

       hist = []
       self.assertRaises(AssertionError, list, chain(gen1(), gen2(False)))
       self.assertEqual(hist, [0,1])

       hist = []
       self.assertRaises(AssertionError, list, chain(gen1(), gen2(True)))
       self.assertEqual(hist, [0,1])

       hist = []
       self.assertRaises(AssertionError, list, cycle(gen1()))
       self.assertEqual(hist, [0,1])

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
>>> 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, None, 2):
...    print name.title()
...
Alex
Laura
Martin
Walter
Samuele

>>> from operator import itemgetter
>>> d = dict(a=1, b=2, c=1, d=2, e=1, f=2, g=3)
>>> di = sorted(d.iteritems(), key=itemgetter(1))
>>> for k, g in groupby(di, itemgetter(1)):
...     print k, map(itemgetter(0), g)
...
1 ['a', 'c', 'e']
2 ['b', 'd', 'f']
3 ['g']

# Find runs of consecutive numbers using groupby.  The key to the solution
# is differencing with a range so that consecutive numbers all appear in
# same group.
>>> data = [ 1,  4,5,6, 10, 15,16,17,18, 22, 25,26,27,28]
>>> for k, g in groupby(enumerate(data), lambda (i,x):i-x):
...     print map(operator.itemgetter(1), g)
...
[1]
[4, 5, 6]
[10]
[15, 16, 17, 18]
[22]
[25, 26, 27, 28]

>>> def take(n, seq):
...     return list(islice(seq, n))

>>> 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(seq, pred=bool):
...     "Returns True if pred(x) is True for every element in the iterable"
...     for elem in ifilterfalse(pred, seq):
...         return False
...     return True

>>> def any(seq, pred=bool):
...     "Returns True if pred(x) is True for at least one element in the iterable"
...     for elem in ifilter(pred, seq):
...         return True
...     return False

>>> def no(seq, pred=bool):
...     "Returns True if pred(x) is False for every element in the iterable"
...     for elem in ifilter(pred, seq):
...         return False
...     return True

>>> def quantify(seq, pred=bool):
...     "Count how many times the predicate is True in the sequence"
...     return sum(imap(pred, seq))

>>> def padnone(seq):
...     "Returns the sequence elements and then returns None indefinitely"
...     return chain(seq, repeat(None))

>>> def ncycles(seq, n):
...     "Returns the sequence elements n times"
...     return chain(*repeat(seq, n))

>>> def dotproduct(vec1, vec2):
...     return sum(imap(operator.mul, vec1, vec2))

>>> def flatten(listOfLists):
...     return list(chain(*listOfLists))

>>> def repeatfunc(func, times=None, *args):
...     "Repeat calls to func with specified arguments."
...     "   Example:  repeatfunc(random.random)"
...     if times is None:
...         return starmap(func, repeat(args))
...     else:
...         return starmap(func, repeat(args, times))

>>> def pairwise(iterable):
...     "s -> (s0,s1), (s1,s2), (s2, s3), ..."
...     a, b = tee(iterable)
...     try:
...         b.next()
...     except StopIteration:
...         pass
...     return izip(a, b)

This is not part of the examples but it tests to make sure the definitions
perform as purported.

>>> take(10, count())
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

>>> list(enumerate('abc'))
[(0, 'a'), (1, 'b'), (2, 'c')]

>>> list(islice(tabulate(lambda x: 2*x), 4))
[0, 2, 4, 6]

>>> nth('abcde', 3)
['d']

>>> all([2, 4, 6, 8], lambda x: x%2==0)
True

>>> all([2, 3, 6, 8], lambda x: x%2==0)
False

>>> any([2, 4, 6, 8], lambda x: x%2==0)
True

>>> any([1, 3, 5, 9], lambda x: x%2==0,)
False

>>> no([1, 3, 5, 9], lambda x: x%2==0)
True

>>> no([1, 2, 5, 9], lambda x: x%2==0)
False

>>> quantify(xrange(99), lambda x: x%2==0)
50

>>> a = [[1, 2, 3], [4, 5, 6]]
>>> flatten(a)
[1, 2, 3, 4, 5, 6]

>>> list(repeatfunc(pow, 5, 2, 3))
[8, 8, 8, 8, 8]

>>> import random
>>> take(5, imap(int, repeatfunc(random.random)))
[0, 0, 0, 0, 0]

>>> list(pairwise('abcd'))
[('a', 'b'), ('b', 'c'), ('c', 'd')]

>>> list(pairwise([]))
[]

>>> list(pairwise('a'))
[]

>>> list(islice(padnone('abc'), 0, 6))
['a', 'b', 'c', None, None, None]

>>> list(ncycles('abc', 3))
['a', 'b', 'c', 'a', 'b', 'c', 'a', 'b', 'c']

>>> dotproduct([1,2,3], [4,5,6])
32

"""

__test__ = {'libreftest' : libreftest}

def test_main(verbose=None):
   test_classes = (TestBasicOps, TestVariousIteratorArgs, TestGC,
                   RegressionTests, LengthTransparency)
   test_support.run_unittest(*test_classes)

   # verify reference counting
   if verbose and hasattr(sys, "gettotalrefcount"):
       import gc
       counts = [None] * 5
       for i in xrange(len(counts)):
           test_support.run_unittest(*test_classes)
           gc.collect()
           counts[i] = sys.gettotalrefcount()
       print counts

   # doctest the examples in the library reference
   test_support.run_doctest(sys.modules[__name__], verbose)

if __name__ == "__main__":
   test_main(verbose=True)