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')
self.assertRaises(OverflowError, list, islice(count(sys.maxint-5), 10))
c = count(3)
self.assertEqual(repr(c), 'count(3)')
c.next()
self.assertEqual(repr(c), 'count(4)')
c = count(-9)
self.assertEqual(repr(c), 'count(-9)')
c.next()
self.assertEqual(c.next(), -8)
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), None, None)), range(10))
self.assertEqual(list(islice(xrange(10), None, None, 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 number of items consumed SF #1171417
it = iter(range(10))
self.assertEqual(list(islice(it, 3)), range(3))
self.assertEqual(list(it), range(3, 10))
# 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')
self.assertRaises(ValueError, tee, [], -1)
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):
from test.test_iterlen import len
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])
class SubclassWithKwargsTest(unittest.TestCase):
def test_keywords_in_subclass(self):
# count is not subclassable...
for cls in (repeat, izip, ifilter, ifilterfalse, chain, imap,
starmap, islice, takewhile, dropwhile, cycle):
class Subclass(cls):
def __init__(self, newarg=None, *args):
cls.__init__(self, *args)
try:
Subclass(newarg=1)
except TypeError, err:
# we expect type errors because of wrong argument count
self.failIf("does not take keyword arguments" in err.args[0])
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(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=None):
... "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=None):
... "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=None):
... "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=None):
... "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,
SubclassWithKwargsTest)
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)
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