diff options
Diffstat (limited to 'Lib/test/test_itertools.py')
| -rw-r--r-- | Lib/test/test_itertools.py | 150 |
1 files changed, 144 insertions, 6 deletions
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py index 0692747..135973e 100644 --- a/Lib/test/test_itertools.py +++ b/Lib/test/test_itertools.py @@ -49,11 +49,19 @@ def fact(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, list,chain(2, 3)) + + def chain2(*iterables): + 'Pure python version in the docs' + for it in iterables: + for element in it: + yield element + + for c in (chain, chain2): + self.assertEqual(list(c('abc', 'def')), list('abcdef')) + self.assertEqual(list(c('abc')), list('abc')) + self.assertEqual(list(c('')), []) + self.assertEqual(take(4, c('abc', 'def')), list('abcd')) + self.assertRaises(TypeError, list,c(2, 3)) def test_chain_from_iterable(self): self.assertEqual(list(chain.from_iterable(['abc', 'def'])), list('abcdef')) @@ -652,6 +660,81 @@ class TestBasicOps(unittest.TestCase): self.assertRaises(StopIteration, f(lambda x:x, []).next) self.assertRaises(StopIteration, f(lambda x:x, StopNow()).next) +class TestExamples(unittest.TestCase): + + def test_chain(self): + self.assertEqual(''.join(chain('ABC', 'DEF')), 'ABCDEF') + + def test_chain_from_iterable(self): + self.assertEqual(''.join(chain.from_iterable(['ABC', 'DEF'])), 'ABCDEF') + + def test_combinations(self): + self.assertEqual(list(combinations('ABCD', 2)), + [('A','B'), ('A','C'), ('A','D'), ('B','C'), ('B','D'), ('C','D')]) + self.assertEqual(list(combinations(range(4), 3)), + [(0,1,2), (0,1,3), (0,2,3), (1,2,3)]) + + def test_count(self): + self.assertEqual(list(islice(count(10), 5)), [10, 11, 12, 13, 14]) + + def test_cycle(self): + self.assertEqual(list(islice(cycle('ABCD'), 12)), list('ABCDABCDABCD')) + + def test_dropwhile(self): + self.assertEqual(list(dropwhile(lambda x: x<5, [1,4,6,4,1])), [6,4,1]) + + def test_groupby(self): + self.assertEqual([k for k, g in groupby('AAAABBBCCDAABBB')], + list('ABCDAB')) + self.assertEqual([(list(g)) for k, g in groupby('AAAABBBCCD')], + [list('AAAA'), list('BBB'), list('CC'), list('D')]) + + def test_ifilter(self): + self.assertEqual(list(ifilter(lambda x: x%2, range(10))), [1,3,5,7,9]) + + def test_ifilterfalse(self): + self.assertEqual(list(ifilterfalse(lambda x: x%2, range(10))), [0,2,4,6,8]) + + def test_imap(self): + self.assertEqual(list(imap(pow, (2,3,10), (5,2,3))), [32, 9, 1000]) + + def test_islice(self): + self.assertEqual(list(islice('ABCDEFG', 2)), list('AB')) + self.assertEqual(list(islice('ABCDEFG', 2, 4)), list('CD')) + self.assertEqual(list(islice('ABCDEFG', 2, None)), list('CDEFG')) + self.assertEqual(list(islice('ABCDEFG', 0, None, 2)), list('ACEG')) + + def test_izip(self): + self.assertEqual(list(izip('ABCD', 'xy')), [('A', 'x'), ('B', 'y')]) + + def test_izip_longest(self): + self.assertEqual(list(izip_longest('ABCD', 'xy', fillvalue='-')), + [('A', 'x'), ('B', 'y'), ('C', '-'), ('D', '-')]) + + def test_permutations(self): + self.assertEqual(list(permutations('ABCD', 2)), + map(tuple, 'AB AC AD BA BC BD CA CB CD DA DB DC'.split())) + self.assertEqual(list(permutations(range(3))), + [(0,1,2), (0,2,1), (1,0,2), (1,2,0), (2,0,1), (2,1,0)]) + + def test_product(self): + self.assertEqual(list(product('ABCD', 'xy')), + map(tuple, 'Ax Ay Bx By Cx Cy Dx Dy'.split())) + self.assertEqual(list(product(range(2), repeat=3)), + [(0,0,0), (0,0,1), (0,1,0), (0,1,1), + (1,0,0), (1,0,1), (1,1,0), (1,1,1)]) + + def test_repeat(self): + self.assertEqual(list(repeat(10, 3)), [10, 10, 10]) + + def test_stapmap(self): + self.assertEqual(list(starmap(pow, [(2,5), (3,2), (10,3)])), + [32, 9, 1000]) + + def test_takewhile(self): + self.assertEqual(list(takewhile(lambda x: x<5, [1,4,6,4,1])), [1,4]) + + class TestGC(unittest.TestCase): def makecycle(self, iterator, container): @@ -663,6 +746,14 @@ class TestGC(unittest.TestCase): a = [] self.makecycle(chain(a), a) + def test_chain_from_iterable(self): + a = [] + self.makecycle(chain.from_iterable([a]), a) + + def test_combinations(self): + a = [] + self.makecycle(combinations([1,2,a,3], 3), a) + def test_cycle(self): a = [] self.makecycle(cycle([a]*2), a) @@ -687,6 +778,12 @@ class TestGC(unittest.TestCase): a = [] self.makecycle(izip([a]*2, [a]*3), a) + def test_izip_longest(self): + a = [] + self.makecycle(izip_longest([a]*2, [a]*3), a) + b = [a, None] + self.makecycle(izip_longest([a]*2, [a]*3, fillvalue=b), a) + def test_imap(self): a = [] self.makecycle(imap(lambda x:x, [a]*2), a) @@ -695,6 +792,14 @@ class TestGC(unittest.TestCase): a = [] self.makecycle(islice([a]*2, None), a) + def test_permutations(self): + a = [] + self.makecycle(permutations([1,2,a,3], 3), a) + + def test_product(self): + a = [] + self.makecycle(product([1,2,a,3], repeat=3), a) + def test_repeat(self): a = [] self.makecycle(repeat(a), a) @@ -1120,6 +1225,30 @@ Samuele ... pass ... return izip(a, b) +>>> def grouper(n, iterable, padvalue=None): +... "grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')" +... return izip(*[chain(iterable, repeat(padvalue, n-1))]*n) + +>>> def roundrobin(*iterables): +... "roundrobin('abc', 'd', 'ef') --> 'a', 'd', 'e', 'b', 'f', 'c'" +... # Recipe credited to George Sakkis +... pending = len(iterables) +... nexts = cycle(iter(it).next for it in iterables) +... while pending: +... try: +... for next in nexts: +... yield next() +... except StopIteration: +... pending -= 1 +... nexts = cycle(islice(nexts, pending)) + +>>> def powerset(iterable): +... "powerset('ab') --> set([]), set(['a']), set(['b']), set(['a', 'b'])" +... # Recipe credited to Eric Raymond +... pairs = [(2**i, x) for i, x in enumerate(iterable)] +... for n in xrange(2**len(pairs)): +... yield set(x for m, x in pairs if m&n) + This is not part of the examples but it tests to make sure the definitions perform as purported. @@ -1185,6 +1314,15 @@ False >>> dotproduct([1,2,3], [4,5,6]) 32 +>>> list(grouper(3, 'abcdefg', 'x')) +[('a', 'b', 'c'), ('d', 'e', 'f'), ('g', 'x', 'x')] + +>>> list(roundrobin('abc', 'd', 'ef')) +['a', 'd', 'e', 'b', 'f', 'c'] + +>>> map(sorted, powerset('ab')) +[[], ['a'], ['b'], ['a', 'b']] + """ __test__ = {'libreftest' : libreftest} @@ -1192,7 +1330,7 @@ __test__ = {'libreftest' : libreftest} def test_main(verbose=None): test_classes = (TestBasicOps, TestVariousIteratorArgs, TestGC, RegressionTests, LengthTransparency, - SubclassWithKwargsTest) + SubclassWithKwargsTest, TestExamples) test_support.run_unittest(*test_classes) # verify reference counting |