cocorobolx/python/skulpt/test/unit/test_iter.py

import unittest
from time import sleep
# from test.test_support import run_unittest, TESTFN, unlink, have_unicode, \
#                               check_py3k_warnings, cpython_only

# Test result of triple loop (too big to inline)
TRIPLETS = [(0, 0, 0), (0, 0, 1), (0, 0, 2),
            (0, 1, 0), (0, 1, 1), (0, 1, 2),
            (0, 2, 0), (0, 2, 1), (0, 2, 2),

            (1, 0, 0), (1, 0, 1), (1, 0, 2),
            (1, 1, 0), (1, 1, 1), (1, 1, 2),
            (1, 2, 0), (1, 2, 1), (1, 2, 2),

            (2, 0, 0), (2, 0, 1), (2, 0, 2),
            (2, 1, 0), (2, 1, 1), (2, 1, 2),
            (2, 2, 0), (2, 2, 1), (2, 2, 2)]

# Helper classes

class BasicIterClass:
    def __init__(self, n):
        self.n = n
        self.i = 0
    def next(self):
        res = self.i
        if res >= self.n:
            raise StopIteration
        self.i = res + 1
        return res

class IteratingSequenceClass:
    def __init__(self, n):
        self.n = n
    def __iter__(self):
        return BasicIterClass(self.n)

class SleepingIterClass(BasicIterClass):
    def __init__(self, n):
        BasicIterClass.__init__(self, n)
    def next(self):
        sleep(0.01)
        return BasicIterClass.next(self)

class SleepingSequenceClass:
    def __init__(self, n):
        self.n = n
    def __iter__(self):
        return SleepingIterClass(self.n)

class SequenceClass:
    def __init__(self, n):
        self.n = n
    def __getitem__(self, i):
        if 0 <= i < self.n:
            return i
        else:
            raise IndexError

# Main test suite

class TestCase(unittest.TestCase):

    # Helper to check that an iterator returns a given sequence
    def check_iterator(self, it, seq):
        res = []
        while 1:
            try:
                val = it.next()
            except StopIteration:
                break
            res.append(val)
        self.assertEqual(res, seq)

    # Helper to check that a for loop generates a given sequence
    def check_for_loop(self, expr, seq):
        res = []
        for val in expr:
            res.append(val)
        self.assertEqual(res, seq)

    # Test basic use of iter() function
    def test_iter_basic(self):
        self.check_iterator(iter(range(10)), range(10))

    # Test that iter(iter(x)) is the same as iter(x)
    def test_iter_idempotency(self):
        seq = range(10)
        it = iter(seq)
        it2 = iter(it)
        self.assertTrue(it is it2)

    # Test that for loops over iterators work
    def test_iter_for_loop(self):
        self.check_for_loop(iter(range(10)), range(10))

    # Test several independent iterators over the same list
    def test_iter_independence(self):
        seq = range(3)
        res = []
        for i in iter(seq):
            for j in iter(seq):
                for k in iter(seq):
                    res.append((i, j, k))
        self.assertEqual(res, TRIPLETS)

    # Test triple list comprehension using iterators
    def test_nested_comprehensions_iter(self):
        seq = range(3)
        res = [(i, j, k)
               for i in iter(seq) for j in iter(seq) for k in iter(seq)]
        self.assertEqual(res, TRIPLETS)

    # Test triple list comprehension without iterators
    def test_nested_comprehensions_for(self):
        seq = range(3)
        res = [(i, j, k) for i in seq for j in seq for k in seq]
        self.assertEqual(res, TRIPLETS)

    # Test a class with __iter__ in a for loop
    def test_iter_class_for(self):
        self.check_for_loop(IteratingSequenceClass(10), range(10))

    # Test a class with a suspending iterator in a for loop
    def test_iter_sleeping_class_for(self):
        self.check_for_loop(SleepingSequenceClass(10), range(10))

    # Test a class with __iter__ with explicit iter()
    def test_iter_class_iter(self):
        self.check_iterator(iter(IteratingSequenceClass(10)), range(10))

    # Test for loop on a sequence class without __iter__
    def test_seq_class_for(self):
        self.check_for_loop(SequenceClass(10), range(10))

    # Test iter() on a sequence class without __iter__
    def test_seq_class_iter(self):
        self.check_iterator(iter(SequenceClass(10)), range(10))

    # Test a new_style class with __iter__ but no next() method
    # def test_new_style_iter_class(self):
    #     class IterClass(object):
    #         def __iter__(self):
    #             return self
    #     self.assertRaises(TypeError, iter, IterClass())

    # Test two-argument iter() with callable instance
    def test_iter_callable(self):
        class C:
            def __init__(self):
                self.i = 0
            def __call__(self):
                i = self.i
                self.i = i + 1
                if i > 100:
                    raise IndexError # Emergency stop
                return i
        self.check_iterator(iter(C(), 10), range(10))

    # Test two-argument iter() with function
    def test_iter_function(self):
        def spam(state=[0]):
            i = state[0]
            state[0] = i+1
            return i
        self.check_iterator(iter(spam, 10), range(10))

    # Test two-argument iter() with function that raises StopIteration
    def test_iter_function_stop(self):
        def spam(state=[0]):
            i = state[0]
            if i == 10:
                raise StopIteration
            state[0] = i+1
            return i
        self.check_iterator(iter(spam, 20), range(10))

    # Test exception propagation through function iterator
    def test_exception_function(self):
        def spam(state=[0]):
            i = state[0]
            state[0] = i+1
            if i == 10:
                raise RuntimeError
            return i
        res = []

        try:
            for x in iter(spam, 20):
                res.append(x)
        except RuntimeError:
            self.assertEqual(res, range(10))
        else:
            self.fail("should have raised RuntimeError")

    # Test exception propagation through sequence iterator
    def test_exception_sequence(self):
        class MySequenceClass(SequenceClass):
            def __getitem__(self, i):
                if i == 10:
                    raise RuntimeError
                return SequenceClass.__getitem__(self, i)
        res = []
        try:
            for x in MySequenceClass(20):
                res.append(x)
        except RuntimeError:
            self.assertEqual(res, range(10))
        else:
            self.fail("should have raised RuntimeError")

    # Test exception propagation through explicit iterator
    #def test_exception_iter(self):
    #    class MyIterClass(object):
    #        def __init__(self):
    #            self.i = -1
    #            SequenceClass.__init__(self)

    #        def next(self):
    #            self.i += 1
    #            if self.i == 10:
    #                raise RuntimeError
    #            return self.i

    #    class MySequenceClass(SequenceClass):
    #        def __iter__(self):
    #            return MyIterClass()

    #    res = []
    #    try:
    #        for x in MySequenceClass(20):
    #            res.append(x)
    #    except RuntimeError:
    #        self.assertEqual(res, range(10))
    #    else:
    #        self.fail("should have raised RuntimeError")

    # Test for StopIteration from __getitem__
    def test_stop_sequence(self):
        class MySequenceClass(SequenceClass):
            def __getitem__(self, i):
                if i == 10:
                    raise StopIteration
                return SequenceClass.__getitem__(self, i)
        self.check_for_loop(MySequenceClass(20), range(10))

    # Test a big range
    def test_iter_big_range(self):
        self.check_for_loop(iter(range(10000)), range(10000))

    # Test an empty list
    def test_iter_empty(self):
        self.check_for_loop(iter([]), [])

    # Test a tuple
    def test_iter_tuple(self):
        self.check_for_loop(iter((0,1,2,3,4,5,6,7,8,9)), range(10))

    # Test an xrange
    def test_iter_xrange(self):
        self.check_for_loop(iter(xrange(10)), range(10))

    # Test a string
    def test_iter_string(self):
        self.check_for_loop(iter("abcde"), ["a", "b", "c", "d", "e"])

    # Test a Unicode string
    # if have_unicode:
    #     def test_iter_unicode(self):
    #         self.check_for_loop(iter(unicode("abcde")),
    #                             [unicode("a"), unicode("b"), unicode("c"),
    #                              unicode("d"), unicode("e")])

    # Test a directory
    def test_iter_dict(self):
        dict = {}
        for i in range(10):
            dict[i] = None
        self.check_for_loop(dict, dict.keys())

    # Test a file
    # def test_iter_file(self):
    #     f = open(TESTFN, "w")
    #     try:
    #         for i in range(5):
    #             f.write("%d\n" % i)
    #     finally:
    #         f.close()
    #     f = open(TESTFN, "r")
    #     try:
    #         self.check_for_loop(f, ["0\n", "1\n", "2\n", "3\n", "4\n"])
    #         self.check_for_loop(f, [])
    #     finally:
    #         f.close()
    #         try:
    #             unlink(TESTFN)
    #         except OSError:
    #             pass

    # Test list()'s use of iterators.
    def test_builtin_list(self):
        self.assertEqual(list(SequenceClass(5)), range(5))
        self.assertEqual(list(SequenceClass(0)), [])
        self.assertEqual(list(()), [])
        self.assertEqual(list(range(10, -1, -1)), range(10, -1, -1))

        d = {"one": 1, "two": 2, "three": 3}
        self.assertEqual(list(d), d.keys())

        self.assertRaises(TypeError, list, list)
        self.assertRaises(TypeError, list, 42)

        # f = open(TESTFN, "w")
        # try:
        #     for i in range(5):
        #         f.write("%d\n" % i)
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     self.assertEqual(list(f), ["0\n", "1\n", "2\n", "3\n", "4\n"])
        #     f.seek(0, 0)
        #     self.assertEqual(list(f),
        #                      ["0\n", "1\n", "2\n", "3\n", "4\n"])
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

    # Test tuples()'s use of iterators.
    def test_builtin_tuple(self):
        self.assertEqual(tuple(SequenceClass(5)), (0, 1, 2, 3, 4))
        self.assertEqual(tuple(SequenceClass(0)), ())
        self.assertEqual(tuple([]), ())
        self.assertEqual(tuple(()), ())
        self.assertEqual(tuple("abc"), ("a", "b", "c"))

        d = {"one": 1, "two": 2, "three": 3}
        self.assertEqual(tuple(d), tuple(d.keys()))

        self.assertRaises(TypeError, tuple, list)
        self.assertRaises(TypeError, tuple, 42)

        # f = open(TESTFN, "w")
        # try:
        #     for i in range(5):
        #         f.write("%d\n" % i)
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     self.assertEqual(tuple(f), ("0\n", "1\n", "2\n", "3\n", "4\n"))
        #     f.seek(0, 0)
        #     self.assertEqual(tuple(f),
        #                      ("0\n", "1\n", "2\n", "3\n", "4\n"))
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

    # Test filter()'s use of iterators.
    def test_builtin_filter(self):
        self.assertEqual(filter(None, SequenceClass(5)), range(1, 5))
        self.assertEqual(filter(None, SequenceClass(0)), [])
        self.assertEqual(filter(None, ()), ())
        self.assertEqual(filter(None, "abc"), "abc")

        d = {"one": 1, "two": 2, "three": 3}
        self.assertEqual(filter(None, d), d.keys())

        self.assertRaises(TypeError, filter, None, list)
        self.assertRaises(TypeError, filter, None, 42)

        class Boolean:
            def __init__(self, truth):
                self.truth = truth
            def __nonzero__(self):
                return self.truth
        bTrue = Boolean(1)
        bFalse = Boolean(0)

        class Seq:
            def __init__(self, *args):
                self.vals = args
            def __iter__(self):
                class SeqIter:
                    def __init__(self, vals):
                        self.vals = vals
                        self.i = 0
                    def __iter__(self):
                        return self
                    def next(self):
                        i = self.i
                        self.i = i + 1
                        if i < len(self.vals):
                            return self.vals[i]
                        else:
                            raise StopIteration
                return SeqIter(self.vals)

        seq = Seq(*([bTrue, bFalse] * 25))
        self.assertEqual(filter(lambda x: not x, seq), [bFalse]*25)
        # self.assertEqual(filter(lambda x: not x, iter(seq)), [bFalse]*25)

    # Test max() and min()'s use of iterators.
    def test_builtin_max_min(self):
        self.assertEqual(max(SequenceClass(5)), 4)
        self.assertEqual(min(SequenceClass(5)), 0)
        self.assertEqual(max(8, -1), 8)
        self.assertEqual(min(8, -1), -1)

        d = {"one": 1, "two": 2, "three": 3}
        self.assertEqual(max(d), "two")
        self.assertEqual(min(d), "one")
        #self.assertEqual(max(d.itervalues()), 3)
        #self.assertEqual(min(iter(d.itervalues())), 1)

        # f = open(TESTFN, "w")
        # try:
        #     f.write("medium line\n")
        #     f.write("xtra large line\n")
        #     f.write("itty-bitty line\n")
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     self.assertEqual(min(f), "itty-bitty line\n")
        #     f.seek(0, 0)
        #     self.assertEqual(max(f), "xtra large line\n")
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

    # Test map()'s use of iterators.
    def test_builtin_map(self):
        self.assertEqual(map(lambda x: x+1, SequenceClass(5)), range(1, 6))

        d = {"one": 1, "two": 2, "three": 3}
        self.assertEqual(map(lambda k, d=d: (k, d[k]), d), d.items())
        dkeys = d.keys()
        expected = [(i < len(d) and dkeys[i] or None,
                     i,
                     i < len(d) and dkeys[i] or None)
                    for i in range(5)]

        # Deprecated map(None, ...)
        # with check_py3k_warnings():
        #     self.assertEqual(map(None, SequenceClass(5)), range(5))
        #     self.assertEqual(map(None, d), d.keys())
        #     self.assertEqual(map(None, d,
        #                                SequenceClass(5),
        #                                iter(d.iterkeys())),
        #                      expected)

        # f = open(TESTFN, "w")
        # try:
        #     for i in range(10):
        #         f.write("xy" * i + "\n") # line i has len 2*i+1
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     self.assertEqual(map(len, f), range(1, 21, 2))
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

    # Test zip()'s use of iterators.
    def test_builtin_zip(self):
        self.assertEqual(zip(), [])
        self.assertEqual(zip(*[]), [])
        self.assertEqual(zip(*[(1, 2), 'ab']), [(1, 'a'), (2, 'b')])

        self.assertRaises(TypeError, zip, None)
        self.assertRaises(TypeError, zip, range(10), 42)
        self.assertRaises(TypeError, zip, range(10), zip)

        self.assertEqual(zip(IteratingSequenceClass(3)),
                         [(0,), (1,), (2,)])
        self.assertEqual(zip(SequenceClass(3)),
                         [(0,), (1,), (2,)])

        d = {"one": 1, "two": 2, "three": 3}
        #self.assertEqual(d.items(), zip(d, d.itervalues()))
        self.assertEqual(d.items(), zip(d, d.values()))

        # Generate all ints starting at constructor arg.
        class IntsFrom:
            def __init__(self, start):
                self.i = start

            def __iter__(self):
                return self

            def next(self):
                i = self.i
                self.i = i+1
                return i

        # f = open(TESTFN, "w")
        # try:
        #     f.write("a\n" "bbb\n" "cc\n")
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     self.assertEqual(zip(IntsFrom(0), f, IntsFrom(-100)),
        #                      [(0, "a\n", -100),
        #                       (1, "bbb\n", -99),
        #                       (2, "cc\n", -98)])
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

        self.assertEqual(zip(xrange(5)), [(i,) for i in range(5)])

        # Classes that lie about their lengths.
        class NoGuessLen5:
            def __getitem__(self, i):
                if i >= 5:
                    raise IndexError
                return i

        class Guess3Len5(NoGuessLen5):
            def __len__(self):
                return 3

        class Guess30Len5(NoGuessLen5):
            def __len__(self):
                return 30

        self.assertEqual(len(Guess3Len5()), 3)
        self.assertEqual(len(Guess30Len5()), 30)
        self.assertEqual(zip(NoGuessLen5()), zip(range(5)))
        self.assertEqual(zip(Guess3Len5()), zip(range(5)))
        self.assertEqual(zip(Guess30Len5()), zip(range(5)))

        expected = [(i, i) for i in range(5)]
        for x in NoGuessLen5(), Guess3Len5(), Guess30Len5():
            for y in NoGuessLen5(), Guess3Len5(), Guess30Len5():
                self.assertEqual(zip(x, y), expected)

    # Test reduces()'s use of iterators.
    # def test_deprecated_builtin_reduce(self):
    #     with check_py3k_warnings():
    #         self._test_builtin_reduce()

    def _test_builtin_reduce(self):
        from operator import add
        self.assertEqual(reduce(add, SequenceClass(5)), 10)
        self.assertEqual(reduce(add, SequenceClass(5), 42), 52)
        self.assertRaises(TypeError, reduce, add, SequenceClass(0))
        self.assertEqual(reduce(add, SequenceClass(0), 42), 42)
        self.assertEqual(reduce(add, SequenceClass(1)), 0)
        self.assertEqual(reduce(add, SequenceClass(1), 42), 42)

        d = {"one": 1, "two": 2, "three": 3}
        self.assertEqual(reduce(add, d), "".join(d.keys()))

    # @unittest.skipUnless(have_unicode, 'needs unicode support')
    # def test_unicode_join_endcase(self):

    #     # This class inserts a Unicode object into its argument's natural
    #     # iteration, in the 3rd position.
    #     class OhPhooey:
    #         def __init__(self, seq):
    #             self.it = iter(seq)
    #             self.i = 0

    #         def __iter__(self):
    #             return self

    #         def next(self):
    #             i = self.i
    #             self.i = i+1
    #             if i == 2:
    #                 return unicode("fooled you!")
    #             return self.it.next()

    #     f = open(TESTFN, "w")
    #     try:
    #         f.write("a\n" + "b\n" + "c\n")
    #     finally:
    #         f.close()

    #     f = open(TESTFN, "r")
    #     # Nasty:  string.join(s) can't know whether unicode.join() is needed
    #     # until it's seen all of s's elements.  But in this case, f's
    #     # iterator cannot be restarted.  So what we're testing here is
    #     # whether string.join() can manage to remember everything it's seen
    #     # and pass that on to unicode.join().
    #     try:
    #         got = " - ".join(OhPhooey(f))
    #         self.assertEqual(got, unicode("a\n - b\n - fooled you! - c\n"))
    #     finally:
    #         f.close()
    #         try:
    #             unlink(TESTFN)
    #         except OSError:
    #             pass

    # Test iterators with 'x in y' and 'x not in y'.
    def test_in_and_not_in(self):
        for sc5 in IteratingSequenceClass(5), SequenceClass(5):
            for i in range(5):
                self.assertIn(i, sc5)
            for i in "abc", -1, 5, 42.42, (3, 4), [], {1: 1}, 3-12j, sc5:
                self.assertNotIn(i, sc5)

        self.assertRaises(TypeError, lambda: 3 in 12)
        self.assertRaises(TypeError, lambda: 3 not in map)

        d = {"one": 1, "two": 2, "three": 3, 1j: 2j}
        for k in d:
            self.assertIn(k, d)
            #self.assertNotIn(k, d.itervalues())

        for v in d.values():
            #self.assertIn(v, d.itervalues())
            self.assertNotIn(v, d)
        #for k, v in d.iteritems():
        #    self.assertIn((k, v), d.iteritems())
        #    self.assertNotIn((v, k), d.iteritems())

        # f = open(TESTFN, "w")
        # try:
        #     f.write("a\n" "b\n" "c\n")
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     for chunk in "abc":
        #         f.seek(0, 0)
        #         self.assertNotIn(chunk, f)
        #         f.seek(0, 0)
        #         self.assertIn((chunk + "\n"), f)
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

    # Test iterators with operator.countOf (PySequence_Count).
    def test_countOf(self):
        from operator import countOf
        self.assertEqual(countOf([1,2,2,3,2,5], 2), 3)
        self.assertEqual(countOf((1,2,2,3,2,5), 2), 3)
        self.assertEqual(countOf("122325", "2"), 3)
        self.assertEqual(countOf("122325", "6"), 0)

        self.assertRaises(TypeError, countOf, 42, 1)
        self.assertRaises(TypeError, countOf, countOf, countOf)

        d = {"one": 3, "two": 3, "three": 3, 1j: 2j}
        for k in d:
            self.assertEqual(countOf(d, k), 1)
        #self.assertEqual(countOf(d.itervalues(), 3), 3)
        #self.assertEqual(countOf(d.itervalues(), 2j), 1)
        #self.assertEqual(countOf(d.itervalues(), 1j), 0)

        # f = open(TESTFN, "w")
        # try:
        #     f.write("a\n" "b\n" "c\n" "b\n")
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     for letter, count in ("a", 1), ("b", 2), ("c", 1), ("d", 0):
        #         f.seek(0, 0)
        #         self.assertEqual(countOf(f, letter + "\n"), count)
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

    # Test iterators with operator.indexOf (PySequence_Index).
    def test_indexOf(self):
        from operator import indexOf
        self.assertEqual(indexOf([1,2,2,3,2,5], 1), 0)
        self.assertEqual(indexOf((1,2,2,3,2,5), 2), 1)
        self.assertEqual(indexOf((1,2,2,3,2,5), 3), 3)
        self.assertEqual(indexOf((1,2,2,3,2,5), 5), 5)
        self.assertRaises(ValueError, indexOf, (1,2,2,3,2,5), 0)
        self.assertRaises(ValueError, indexOf, (1,2,2,3,2,5), 6)

        self.assertEqual(indexOf("122325", "2"), 1)
        self.assertEqual(indexOf("122325", "5"), 5)
        self.assertRaises(ValueError, indexOf, "122325", "6")

        self.assertRaises(TypeError, indexOf, 42, 1)
        self.assertRaises(TypeError, indexOf, indexOf, indexOf)

        # f = open(TESTFN, "w")
        # try:
        #     f.write("a\n" "b\n" "c\n" "d\n" "e\n")
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     fiter = iter(f)
        #     self.assertEqual(indexOf(fiter, "b\n"), 1)
        #     self.assertEqual(indexOf(fiter, "d\n"), 1)
        #     self.assertEqual(indexOf(fiter, "e\n"), 0)
        #     self.assertRaises(ValueError, indexOf, fiter, "a\n")
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

        iclass = IteratingSequenceClass(3)
        for i in range(3):
            self.assertEqual(indexOf(iclass, i), i)
        self.assertRaises(ValueError, indexOf, iclass, -1)

    # Test iterators with file.writelines().
    # def test_writelines(self):
    #     f = file(TESTFN, "w")

    #     try:
    #         self.assertRaises(TypeError, f.writelines, None)
    #         self.assertRaises(TypeError, f.writelines, 42)

    #         f.writelines(["1\n", "2\n"])
    #         f.writelines(("3\n", "4\n"))
    #         f.writelines({'5\n': None})
    #         f.writelines({})

    #         # Try a big chunk too.
    #         class Iterator:
    #             def __init__(self, start, finish):
    #                 self.start = start
    #                 self.finish = finish
    #                 self.i = self.start

    #             def next(self):
    #                 if self.i >= self.finish:
    #                     raise StopIteration
    #                 result = str(self.i) + '\n'
    #                 self.i += 1
    #                 return result

    #             def __iter__(self):
    #                 return self

    #         class Whatever:
    #             def __init__(self, start, finish):
    #                 self.start = start
    #                 self.finish = finish

    #             def __iter__(self):
    #                 return Iterator(self.start, self.finish)

    #         f.writelines(Whatever(6, 6+2000))
    #         f.close()

    #         f = file(TESTFN)
    #         expected = [str(i) + "\n" for i in range(1, 2006)]
    #         self.assertEqual(list(f), expected)

    #     finally:
    #         f.close()
    #         try:
    #             unlink(TESTFN)
    #         except OSError:
    #             pass


    # Test iterators on RHS of unpacking assignments.
    def test_unpack_iter(self):
        a, b = 1, 2
        self.assertEqual((a, b), (1, 2))

        a, b, c = IteratingSequenceClass(3)
        self.assertEqual((a, b, c), (0, 1, 2))

        try:    # too many values
            a, b = IteratingSequenceClass(3)
        except ValueError:
            pass
        else:
            self.fail("should have raised ValueError")

        try:    # not enough values
            a, b, c = IteratingSequenceClass(2)
        except ValueError:
            pass
        else:
            self.fail("should have raised ValueError")

        try:    # not iterable
            a, b, c = len
        except TypeError:
            pass
        else:
            self.fail("should have raised TypeError")

        #a, b, c = {1: 42, 2: 42, 3: 42}.itervalues()
        #self.assertEqual((a, b, c), (42, 42, 42))

        # f = open(TESTFN, "w")
        # lines = ("a\n", "bb\n", "ccc\n")
        # try:
        #     for line in lines:
        #         f.write(line)
        # finally:
        #     f.close()
        # f = open(TESTFN, "r")
        # try:
        #     a, b, c = f
        #     self.assertEqual((a, b, c), lines)
        # finally:
        #     f.close()
        #     try:
        #         unlink(TESTFN)
        #     except OSError:
        #         pass

        (a, b), (c,) = IteratingSequenceClass(2), {42: 24}
        self.assertEqual((a, b, c), (0, 1, 42))


    # @cpython_only
    # def test_ref_counting_behavior(self):
    #     class C(object):
    #         count = 0
    #         def __new__(cls):
    #             cls.count += 1
    #             return object.__new__(cls)
    #         def __del__(self):
    #             cls = self.__class__
    #             assert cls.count > 0
    #             cls.count -= 1
    #     x = C()
    #     self.assertEqual(C.count, 1)
    #     del x
    #     self.assertEqual(C.count, 0)
    #     l = [C(), C(), C()]
    #     self.assertEqual(C.count, 3)
    #     try:
    #         a, b = iter(l)
    #     except ValueError:
    #         pass
    #     del l
    #     self.assertEqual(C.count, 0)


    # Make sure StopIteration is a "sink state".
    # This tests various things that weren't sink states in Python 2.2.1,
    # plus various things that always were fine.

    def test_sinkstate_list(self):
        # This used to fail
        a = range(5)
        b = iter(a)
        # print "list of b", list(b)
        # print next(b)
        self.assertEqual(list(b), range(5))
        a.extend(range(5, 10))
        self.assertEqual(list(b), [])

    def test_sinkstate_tuple(self):
        a = (0, 1, 2, 3, 4)
        b = iter(a)
        self.assertEqual(list(b), range(5))
        self.assertEqual(list(b), [])
        

    def test_sinkstate_string(self):
        a = "abcde"
        b = iter(a)
        self.assertEqual(list(b), ['a', 'b', 'c', 'd', 'e'])
        self.assertEqual(list(b), [])

    # def test_sinkstate_callable(self):
    #     # This used to fail
        # a = SequenceClass(5)
        # b = iter(a)
        # self.assertEqual(list(b), range(5))
        # a.n = 10
        # self.assertEqual(list(b), [])

    def test_sinkstate_callable(self):
        # This used to fail
        def spam(state=[0]):
            i = state[0]
            state[0] = i+1
            if i == 10:
                raise AssertionError, "shouldn't have gotten this far"
            return i
        b = iter(spam, 5)
        self.assertEqual(list(b), range(5))
        self.assertEqual(list(b), [])

    # def test_sinkstate_dict(self):
    #     # XXX For a more thorough test, see towards the end of:
    #     # http://mail.python.org/pipermail/python-dev/2002-July/026512.html
    #     a = {1:1, 2:2, 0:0, 4:4, 3:3}
    #     for b in iter(a), a.iterkeys(), a.iteritems(), a.itervalues():
    #         b = iter(a)
    #         self.assertEqual(len(list(b)), 5)
    #         self.assertEqual(list(b), [])

    def test_sinkstate_yield(self):
        def gen():
            for i in range(5):
                yield i
        b = gen()
        self.assertEqual(list(b), range(5))
        self.assertEqual(list(b), [])

    def test_sinkstate_range(self):
        a = xrange(5)
        b = iter(a)
        self.assertEqual(list(b), range(5))
        self.assertEqual(list(b), [])

    def test_sinkstate_enumerate(self):
        a = range(5)
        e = enumerate(a)
        b = iter(e)
        self.assertEqual(list(b), zip(range(5), range(5)))
        self.assertEqual(list(b), [])

    # def test_3720(self):
    #     # Avoid a crash, when an iterator deletes its next() method.
    #     class BadIterator(object):
    #         def __iter__(self):
    #             return self
    #         def next(self):
    #             del BadIterator.next
    #             return 1

    #     try:
    #         for i in BadIterator() :
    #             pass
    #     except TypeError:
    #         pass

    def test_extending_list_with_iterator_does_not_segfault(self):
        # The code to extend a list with an iterator has a fair
        # amount of nontrivial logic in terms of guessing how
        # much memory to allocate in advance, "stealing" refs,
        # and then shrinking at the end.  This is a basic smoke
        # test for that scenario.
        def gen():
            for i in range(500):
                yield i
        lst = [0] * 500
        for i in range(240):
            lst.pop(0)
        lst.extend(gen())
        self.assertEqual(len(lst), 760)



if __name__ == "__main__":
    unittest.main()