import unittest from test import test_support from itertools import * import sys import operator def onearg(x): 'Test function of one argument' return 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 class StopNow: 'Class emulating an empty iterable.' def __iter__(self): return self def next(self): raise StopIteration 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.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.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() def test_cycle(self): self.assertEqual(list(islice(cycle('abc'),10)), 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_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.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.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(list(izip('abcdef')), zip('abcdef')) self.assertRaises(TypeError, izip) 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')) ids = map(id, izip('abc', 'def')) self.assertEqual(min(ids), max(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(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') 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(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(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) 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_StopIteration(self): for f in (chain, cycle, izip): self.assertRaises(StopIteration, f([]).next) self.assertRaises(StopIteration, f(StopNow()).next) self.assertRaises(StopIteration, islice([], None).next) self.assertRaises(StopIteration, islice(StopNow(), None).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) 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, 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))) >>> 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)) This is not part of the examples but it tests to make sure the definitions perform as purported. >>> 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(lambda x: x%2==0, [2, 4, 6, 8]) True >>> all(lambda x: x%2==0, [2, 3, 6, 8]) False >>> some(lambda x: x%2==0, [2, 4, 6, 8]) True >>> some(lambda x: x%2==0, [1, 3, 5, 9]) False >>> no(lambda x: x%2==0, [1, 3, 5, 9]) True >>> no(lambda x: x%2==0, [1, 2, 5, 9]) False >>> list(pairwise('abc')) [('a', 'b'), ('b', 'c')] >>> 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_support.run_unittest(TestBasicOps) # verify reference counting if verbose and hasattr(sys, "gettotalrefcount"): counts = [None] * 5 for i in xrange(len(counts)): test_support.run_unittest(TestBasicOps) 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)