symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_sets.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/test/test_sets.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,860 @@
+#!/usr/bin/env python
+
+import warnings
+warnings.filterwarnings("ignore", "the sets module is deprecated",
+                        DeprecationWarning, "test\.test_sets")
+
+import unittest, operator, copy, pickle, random
+from sets import Set, ImmutableSet
+from test import test_support
+
+empty_set = Set()
+
+#==============================================================================
+
+class TestBasicOps(unittest.TestCase):
+
+    def test_repr(self):
+        if self.repr is not None:
+            self.assertEqual(repr(self.set), self.repr)
+
+    def test_length(self):
+        self.assertEqual(len(self.set), self.length)
+
+    def test_self_equality(self):
+        self.assertEqual(self.set, self.set)
+
+    def test_equivalent_equality(self):
+        self.assertEqual(self.set, self.dup)
+
+    def test_copy(self):
+        self.assertEqual(self.set.copy(), self.dup)
+
+    def test_self_union(self):
+        result = self.set | self.set
+        self.assertEqual(result, self.dup)
+
+    def test_empty_union(self):
+        result = self.set | empty_set
+        self.assertEqual(result, self.dup)
+
+    def test_union_empty(self):
+        result = empty_set | self.set
+        self.assertEqual(result, self.dup)
+
+    def test_self_intersection(self):
+        result = self.set & self.set
+        self.assertEqual(result, self.dup)
+
+    def test_empty_intersection(self):
+        result = self.set & empty_set
+        self.assertEqual(result, empty_set)
+
+    def test_intersection_empty(self):
+        result = empty_set & self.set
+        self.assertEqual(result, empty_set)
+
+    def test_self_symmetric_difference(self):
+        result = self.set ^ self.set
+        self.assertEqual(result, empty_set)
+
+    def checkempty_symmetric_difference(self):
+        result = self.set ^ empty_set
+        self.assertEqual(result, self.set)
+
+    def test_self_difference(self):
+        result = self.set - self.set
+        self.assertEqual(result, empty_set)
+
+    def test_empty_difference(self):
+        result = self.set - empty_set
+        self.assertEqual(result, self.dup)
+
+    def test_empty_difference_rev(self):
+        result = empty_set - self.set
+        self.assertEqual(result, empty_set)
+
+    def test_iteration(self):
+        for v in self.set:
+            self.assert_(v in self.values)
+
+    def test_pickling(self):
+        p = pickle.dumps(self.set)
+        copy = pickle.loads(p)
+        self.assertEqual(self.set, copy,
+                         "%s != %s" % (self.set, copy))
+
+#------------------------------------------------------------------------------
+
+class TestBasicOpsEmpty(TestBasicOps):
+    def setUp(self):
+        self.case   = "empty set"
+        self.values = []
+        self.set    = Set(self.values)
+        self.dup    = Set(self.values)
+        self.length = 0
+        self.repr   = "Set([])"
+
+#------------------------------------------------------------------------------
+
+class TestBasicOpsSingleton(TestBasicOps):
+    def setUp(self):
+        self.case   = "unit set (number)"
+        self.values = [3]
+        self.set    = Set(self.values)
+        self.dup    = Set(self.values)
+        self.length = 1
+        self.repr   = "Set([3])"
+
+    def test_in(self):
+        self.failUnless(3 in self.set)
+
+    def test_not_in(self):
+        self.failUnless(2 not in self.set)
+
+#------------------------------------------------------------------------------
+
+class TestBasicOpsTuple(TestBasicOps):
+    def setUp(self):
+        self.case   = "unit set (tuple)"
+        self.values = [(0, "zero")]
+        self.set    = Set(self.values)
+        self.dup    = Set(self.values)
+        self.length = 1
+        self.repr   = "Set([(0, 'zero')])"
+
+    def test_in(self):
+        self.failUnless((0, "zero") in self.set)
+
+    def test_not_in(self):
+        self.failUnless(9 not in self.set)
+
+#------------------------------------------------------------------------------
+
+class TestBasicOpsTriple(TestBasicOps):
+    def setUp(self):
+        self.case   = "triple set"
+        self.values = [0, "zero", operator.add]
+        self.set    = Set(self.values)
+        self.dup    = Set(self.values)
+        self.length = 3
+        self.repr   = None
+
+#==============================================================================
+
+def baditer():
+    raise TypeError
+    yield True
+
+def gooditer():
+    yield True
+
+class TestExceptionPropagation(unittest.TestCase):
+    """SF 628246:  Set constructor should not trap iterator TypeErrors"""
+
+    def test_instanceWithException(self):
+        self.assertRaises(TypeError, Set, baditer())
+
+    def test_instancesWithoutException(self):
+        # All of these iterables should load without exception.
+        Set([1,2,3])
+        Set((1,2,3))
+        Set({'one':1, 'two':2, 'three':3})
+        Set(xrange(3))
+        Set('abc')
+        Set(gooditer())
+
+#==============================================================================
+
+class TestSetOfSets(unittest.TestCase):
+    def test_constructor(self):
+        inner = Set([1])
+        outer = Set([inner])
+        element = outer.pop()
+        self.assertEqual(type(element), ImmutableSet)
+        outer.add(inner)        # Rebuild set of sets with .add method
+        outer.remove(inner)
+        self.assertEqual(outer, Set())   # Verify that remove worked
+        outer.discard(inner)    # Absence of KeyError indicates working fine
+
+#==============================================================================
+
+class TestBinaryOps(unittest.TestCase):
+    def setUp(self):
+        self.set = Set((2, 4, 6))
+
+    def test_eq(self):              # SF bug 643115
+        self.assertEqual(self.set, Set({2:1,4:3,6:5}))
+
+    def test_union_subset(self):
+        result = self.set | Set([2])
+        self.assertEqual(result, Set((2, 4, 6)))
+
+    def test_union_superset(self):
+        result = self.set | Set([2, 4, 6, 8])
+        self.assertEqual(result, Set([2, 4, 6, 8]))
+
+    def test_union_overlap(self):
+        result = self.set | Set([3, 4, 5])
+        self.assertEqual(result, Set([2, 3, 4, 5, 6]))
+
+    def test_union_non_overlap(self):
+        result = self.set | Set([8])
+        self.assertEqual(result, Set([2, 4, 6, 8]))
+
+    def test_intersection_subset(self):
+        result = self.set & Set((2, 4))
+        self.assertEqual(result, Set((2, 4)))
+
+    def test_intersection_superset(self):
+        result = self.set & Set([2, 4, 6, 8])
+        self.assertEqual(result, Set([2, 4, 6]))
+
+    def test_intersection_overlap(self):
+        result = self.set & Set([3, 4, 5])
+        self.assertEqual(result, Set([4]))
+
+    def test_intersection_non_overlap(self):
+        result = self.set & Set([8])
+        self.assertEqual(result, empty_set)
+
+    def test_sym_difference_subset(self):
+        result = self.set ^ Set((2, 4))
+        self.assertEqual(result, Set([6]))
+
+    def test_sym_difference_superset(self):
+        result = self.set ^ Set((2, 4, 6, 8))
+        self.assertEqual(result, Set([8]))
+
+    def test_sym_difference_overlap(self):
+        result = self.set ^ Set((3, 4, 5))
+        self.assertEqual(result, Set([2, 3, 5, 6]))
+
+    def test_sym_difference_non_overlap(self):
+        result = self.set ^ Set([8])
+        self.assertEqual(result, Set([2, 4, 6, 8]))
+
+    def test_cmp(self):
+        a, b = Set('a'), Set('b')
+        self.assertRaises(TypeError, cmp, a, b)
+
+        # You can view this as a buglet:  cmp(a, a) does not raise TypeError,
+        # because __eq__ is tried before __cmp__, and a.__eq__(a) returns True,
+        # which Python thinks is good enough to synthesize a cmp() result
+        # without calling __cmp__.
+        self.assertEqual(cmp(a, a), 0)
+
+        self.assertRaises(TypeError, cmp, a, 12)
+        self.assertRaises(TypeError, cmp, "abc", a)
+
+    def test_inplace_on_self(self):
+        t = self.set.copy()
+        t |= t
+        self.assertEqual(t, self.set)
+        t &= t
+        self.assertEqual(t, self.set)
+        t -= t
+        self.assertEqual(len(t), 0)
+        t = self.set.copy()
+        t ^= t
+        self.assertEqual(len(t), 0)
+
+
+#==============================================================================
+
+class TestUpdateOps(unittest.TestCase):
+    def setUp(self):
+        self.set = Set((2, 4, 6))
+
+    def test_union_subset(self):
+        self.set |= Set([2])
+        self.assertEqual(self.set, Set((2, 4, 6)))
+
+    def test_union_superset(self):
+        self.set |= Set([2, 4, 6, 8])
+        self.assertEqual(self.set, Set([2, 4, 6, 8]))
+
+    def test_union_overlap(self):
+        self.set |= Set([3, 4, 5])
+        self.assertEqual(self.set, Set([2, 3, 4, 5, 6]))
+
+    def test_union_non_overlap(self):
+        self.set |= Set([8])
+        self.assertEqual(self.set, Set([2, 4, 6, 8]))
+
+    def test_union_method_call(self):
+        self.set.union_update(Set([3, 4, 5]))
+        self.assertEqual(self.set, Set([2, 3, 4, 5, 6]))
+
+    def test_intersection_subset(self):
+        self.set &= Set((2, 4))
+        self.assertEqual(self.set, Set((2, 4)))
+
+    def test_intersection_superset(self):
+        self.set &= Set([2, 4, 6, 8])
+        self.assertEqual(self.set, Set([2, 4, 6]))
+
+    def test_intersection_overlap(self):
+        self.set &= Set([3, 4, 5])
+        self.assertEqual(self.set, Set([4]))
+
+    def test_intersection_non_overlap(self):
+        self.set &= Set([8])
+        self.assertEqual(self.set, empty_set)
+
+    def test_intersection_method_call(self):
+        self.set.intersection_update(Set([3, 4, 5]))
+        self.assertEqual(self.set, Set([4]))
+
+    def test_sym_difference_subset(self):
+        self.set ^= Set((2, 4))
+        self.assertEqual(self.set, Set([6]))
+
+    def test_sym_difference_superset(self):
+        self.set ^= Set((2, 4, 6, 8))
+        self.assertEqual(self.set, Set([8]))
+
+    def test_sym_difference_overlap(self):
+        self.set ^= Set((3, 4, 5))
+        self.assertEqual(self.set, Set([2, 3, 5, 6]))
+
+    def test_sym_difference_non_overlap(self):
+        self.set ^= Set([8])
+        self.assertEqual(self.set, Set([2, 4, 6, 8]))
+
+    def test_sym_difference_method_call(self):
+        self.set.symmetric_difference_update(Set([3, 4, 5]))
+        self.assertEqual(self.set, Set([2, 3, 5, 6]))
+
+    def test_difference_subset(self):
+        self.set -= Set((2, 4))
+        self.assertEqual(self.set, Set([6]))
+
+    def test_difference_superset(self):
+        self.set -= Set((2, 4, 6, 8))
+        self.assertEqual(self.set, Set([]))
+
+    def test_difference_overlap(self):
+        self.set -= Set((3, 4, 5))
+        self.assertEqual(self.set, Set([2, 6]))
+
+    def test_difference_non_overlap(self):
+        self.set -= Set([8])
+        self.assertEqual(self.set, Set([2, 4, 6]))
+
+    def test_difference_method_call(self):
+        self.set.difference_update(Set([3, 4, 5]))
+        self.assertEqual(self.set, Set([2, 6]))
+
+#==============================================================================
+
+class TestMutate(unittest.TestCase):
+    def setUp(self):
+        self.values = ["a", "b", "c"]
+        self.set = Set(self.values)
+
+    def test_add_present(self):
+        self.set.add("c")
+        self.assertEqual(self.set, Set("abc"))
+
+    def test_add_absent(self):
+        self.set.add("d")
+        self.assertEqual(self.set, Set("abcd"))
+
+    def test_add_until_full(self):
+        tmp = Set()
+        expected_len = 0
+        for v in self.values:
+            tmp.add(v)
+            expected_len += 1
+            self.assertEqual(len(tmp), expected_len)
+        self.assertEqual(tmp, self.set)
+
+    def test_remove_present(self):
+        self.set.remove("b")
+        self.assertEqual(self.set, Set("ac"))
+
+    def test_remove_absent(self):
+        try:
+            self.set.remove("d")
+            self.fail("Removing missing element should have raised LookupError")
+        except LookupError:
+            pass
+
+    def test_remove_until_empty(self):
+        expected_len = len(self.set)
+        for v in self.values:
+            self.set.remove(v)
+            expected_len -= 1
+            self.assertEqual(len(self.set), expected_len)
+
+    def test_discard_present(self):
+        self.set.discard("c")
+        self.assertEqual(self.set, Set("ab"))
+
+    def test_discard_absent(self):
+        self.set.discard("d")
+        self.assertEqual(self.set, Set("abc"))
+
+    def test_clear(self):
+        self.set.clear()
+        self.assertEqual(len(self.set), 0)
+
+    def test_pop(self):
+        popped = {}
+        while self.set:
+            popped[self.set.pop()] = None
+        self.assertEqual(len(popped), len(self.values))
+        for v in self.values:
+            self.failUnless(v in popped)
+
+    def test_update_empty_tuple(self):
+        self.set.union_update(())
+        self.assertEqual(self.set, Set(self.values))
+
+    def test_update_unit_tuple_overlap(self):
+        self.set.union_update(("a",))
+        self.assertEqual(self.set, Set(self.values))
+
+    def test_update_unit_tuple_non_overlap(self):
+        self.set.union_update(("a", "z"))
+        self.assertEqual(self.set, Set(self.values + ["z"]))
+
+#==============================================================================
+
+class TestSubsets(unittest.TestCase):
+
+    case2method = {"<=": "issubset",
+                   ">=": "issuperset",
+                  }
+
+    reverse = {"==": "==",
+               "!=": "!=",
+               "<":  ">",
+               ">":  "<",
+               "<=": ">=",
+               ">=": "<=",
+              }
+
+    def test_issubset(self):
+        x = self.left
+        y = self.right
+        for case in "!=", "==", "<", "<=", ">", ">=":
+            expected = case in self.cases
+            # Test the binary infix spelling.
+            result = eval("x" + case + "y", locals())
+            self.assertEqual(result, expected)
+            # Test the "friendly" method-name spelling, if one exists.
+            if case in TestSubsets.case2method:
+                method = getattr(x, TestSubsets.case2method[case])
+                result = method(y)
+                self.assertEqual(result, expected)
+
+            # Now do the same for the operands reversed.
+            rcase = TestSubsets.reverse[case]
+            result = eval("y" + rcase + "x", locals())
+            self.assertEqual(result, expected)
+            if rcase in TestSubsets.case2method:
+                method = getattr(y, TestSubsets.case2method[rcase])
+                result = method(x)
+                self.assertEqual(result, expected)
+#------------------------------------------------------------------------------
+
+class TestSubsetEqualEmpty(TestSubsets):
+    left  = Set()
+    right = Set()
+    name  = "both empty"
+    cases = "==", "<=", ">="
+
+#------------------------------------------------------------------------------
+
+class TestSubsetEqualNonEmpty(TestSubsets):
+    left  = Set([1, 2])
+    right = Set([1, 2])
+    name  = "equal pair"
+    cases = "==", "<=", ">="
+
+#------------------------------------------------------------------------------
+
+class TestSubsetEmptyNonEmpty(TestSubsets):
+    left  = Set()
+    right = Set([1, 2])
+    name  = "one empty, one non-empty"
+    cases = "!=", "<", "<="
+
+#------------------------------------------------------------------------------
+
+class TestSubsetPartial(TestSubsets):
+    left  = Set([1])
+    right = Set([1, 2])
+    name  = "one a non-empty proper subset of other"
+    cases = "!=", "<", "<="
+
+#------------------------------------------------------------------------------
+
+class TestSubsetNonOverlap(TestSubsets):
+    left  = Set([1])
+    right = Set([2])
+    name  = "neither empty, neither contains"
+    cases = "!="
+
+#==============================================================================
+
+class TestOnlySetsInBinaryOps(unittest.TestCase):
+
+    def test_eq_ne(self):
+        # Unlike the others, this is testing that == and != *are* allowed.
+        self.assertEqual(self.other == self.set, False)
+        self.assertEqual(self.set == self.other, False)
+        self.assertEqual(self.other != self.set, True)
+        self.assertEqual(self.set != self.other, True)
+
+    def test_ge_gt_le_lt(self):
+        self.assertRaises(TypeError, lambda: self.set < self.other)
+        self.assertRaises(TypeError, lambda: self.set <= self.other)
+        self.assertRaises(TypeError, lambda: self.set > self.other)
+        self.assertRaises(TypeError, lambda: self.set >= self.other)
+
+        self.assertRaises(TypeError, lambda: self.other < self.set)
+        self.assertRaises(TypeError, lambda: self.other <= self.set)
+        self.assertRaises(TypeError, lambda: self.other > self.set)
+        self.assertRaises(TypeError, lambda: self.other >= self.set)
+
+    def test_union_update_operator(self):
+        try:
+            self.set |= self.other
+        except TypeError:
+            pass
+        else:
+            self.fail("expected TypeError")
+
+    def test_union_update(self):
+        if self.otherIsIterable:
+            self.set.union_update(self.other)
+        else:
+            self.assertRaises(TypeError, self.set.union_update, self.other)
+
+    def test_union(self):
+        self.assertRaises(TypeError, lambda: self.set | self.other)
+        self.assertRaises(TypeError, lambda: self.other | self.set)
+        if self.otherIsIterable:
+            self.set.union(self.other)
+        else:
+            self.assertRaises(TypeError, self.set.union, self.other)
+
+    def test_intersection_update_operator(self):
+        try:
+            self.set &= self.other
+        except TypeError:
+            pass
+        else:
+            self.fail("expected TypeError")
+
+    def test_intersection_update(self):
+        if self.otherIsIterable:
+            self.set.intersection_update(self.other)
+        else:
+            self.assertRaises(TypeError,
+                              self.set.intersection_update,
+                              self.other)
+
+    def test_intersection(self):
+        self.assertRaises(TypeError, lambda: self.set & self.other)
+        self.assertRaises(TypeError, lambda: self.other & self.set)
+        if self.otherIsIterable:
+            self.set.intersection(self.other)
+        else:
+            self.assertRaises(TypeError, self.set.intersection, self.other)
+
+    def test_sym_difference_update_operator(self):
+        try:
+            self.set ^= self.other
+        except TypeError:
+            pass
+        else:
+            self.fail("expected TypeError")
+
+    def test_sym_difference_update(self):
+        if self.otherIsIterable:
+            self.set.symmetric_difference_update(self.other)
+        else:
+            self.assertRaises(TypeError,
+                              self.set.symmetric_difference_update,
+                              self.other)
+
+    def test_sym_difference(self):
+        self.assertRaises(TypeError, lambda: self.set ^ self.other)
+        self.assertRaises(TypeError, lambda: self.other ^ self.set)
+        if self.otherIsIterable:
+            self.set.symmetric_difference(self.other)
+        else:
+            self.assertRaises(TypeError, self.set.symmetric_difference, self.other)
+
+    def test_difference_update_operator(self):
+        try:
+            self.set -= self.other
+        except TypeError:
+            pass
+        else:
+            self.fail("expected TypeError")
+
+    def test_difference_update(self):
+        if self.otherIsIterable:
+            self.set.difference_update(self.other)
+        else:
+            self.assertRaises(TypeError,
+                              self.set.difference_update,
+                              self.other)
+
+    def test_difference(self):
+        self.assertRaises(TypeError, lambda: self.set - self.other)
+        self.assertRaises(TypeError, lambda: self.other - self.set)
+        if self.otherIsIterable:
+            self.set.difference(self.other)
+        else:
+            self.assertRaises(TypeError, self.set.difference, self.other)
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsNumeric(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        self.set   = Set((1, 2, 3))
+        self.other = 19
+        self.otherIsIterable = False
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsDict(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        self.set   = Set((1, 2, 3))
+        self.other = {1:2, 3:4}
+        self.otherIsIterable = True
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsOperator(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        self.set   = Set((1, 2, 3))
+        self.other = operator.add
+        self.otherIsIterable = False
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsTuple(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        self.set   = Set((1, 2, 3))
+        self.other = (2, 4, 6)
+        self.otherIsIterable = True
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsString(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        self.set   = Set((1, 2, 3))
+        self.other = 'abc'
+        self.otherIsIterable = True
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsGenerator(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        def gen():
+            for i in xrange(0, 10, 2):
+                yield i
+        self.set   = Set((1, 2, 3))
+        self.other = gen()
+        self.otherIsIterable = True
+
+#------------------------------------------------------------------------------
+
+class TestOnlySetsofSets(TestOnlySetsInBinaryOps):
+    def setUp(self):
+        self.set   = Set((1, 2, 3))
+        self.other = [Set('ab'), ImmutableSet('cd')]
+        self.otherIsIterable = True
+
+#==============================================================================
+
+class TestCopying(unittest.TestCase):
+
+    def test_copy(self):
+        dup = self.set.copy()
+        dup_list = list(dup); dup_list.sort()
+        set_list = list(self.set); set_list.sort()
+        self.assertEqual(len(dup_list), len(set_list))
+        for i in range(len(dup_list)):
+            self.failUnless(dup_list[i] is set_list[i])
+
+    def test_deep_copy(self):
+        dup = copy.deepcopy(self.set)
+        ##print type(dup), repr(dup)
+        dup_list = list(dup); dup_list.sort()
+        set_list = list(self.set); set_list.sort()
+        self.assertEqual(len(dup_list), len(set_list))
+        for i in range(len(dup_list)):
+            self.assertEqual(dup_list[i], set_list[i])
+
+#------------------------------------------------------------------------------
+
+class TestCopyingEmpty(TestCopying):
+    def setUp(self):
+        self.set = Set()
+
+#------------------------------------------------------------------------------
+
+class TestCopyingSingleton(TestCopying):
+    def setUp(self):
+        self.set = Set(["hello"])
+
+#------------------------------------------------------------------------------
+
+class TestCopyingTriple(TestCopying):
+    def setUp(self):
+        self.set = Set(["zero", 0, None])
+
+#------------------------------------------------------------------------------
+
+class TestCopyingTuple(TestCopying):
+    def setUp(self):
+        self.set = Set([(1, 2)])
+
+#------------------------------------------------------------------------------
+
+class TestCopyingNested(TestCopying):
+    def setUp(self):
+        self.set = Set([((1, 2), (3, 4))])
+
+#==============================================================================
+
+class TestIdentities(unittest.TestCase):
+    def setUp(self):
+        self.a = Set([random.randrange(100) for i in xrange(50)])
+        self.b = Set([random.randrange(100) for i in xrange(50)])
+
+    def test_binopsVsSubsets(self):
+        a, b = self.a, self.b
+        self.assert_(a - b <= a)
+        self.assert_(b - a <= b)
+        self.assert_(a & b <= a)
+        self.assert_(a & b <= b)
+        self.assert_(a | b >= a)
+        self.assert_(a | b >= b)
+        self.assert_(a ^ b <= a | b)
+
+    def test_commutativity(self):
+        a, b = self.a, self.b
+        self.assertEqual(a&b, b&a)
+        self.assertEqual(a|b, b|a)
+        self.assertEqual(a^b, b^a)
+        if a != b:
+            self.assertNotEqual(a-b, b-a)
+
+    def test_reflexsive_relations(self):
+        a, zero = self.a, Set()
+        self.assertEqual(a ^ a, zero)
+        self.assertEqual(a - a, zero)
+        self.assertEqual(a | a, a)
+        self.assertEqual(a & a, a)
+        self.assert_(a <= a)
+        self.assert_(a >= a)
+        self.assert_(a == a)
+
+    def test_summations(self):
+        # check that sums of parts equal the whole
+        a, b = self.a, self.b
+        self.assertEqual((a-b)|(a&b)|(b-a), a|b)
+        self.assertEqual((a&b)|(a^b), a|b)
+        self.assertEqual(a|(b-a), a|b)
+        self.assertEqual((a-b)|b, a|b)
+        self.assertEqual((a-b)|(a&b), a)
+        self.assertEqual((b-a)|(a&b), b)
+        self.assertEqual((a-b)|(b-a), a^b)
+
+    def test_exclusion(self):
+        # check that inverse operations do not overlap
+        a, b, zero = self.a, self.b, Set()
+        self.assertEqual((a-b)&b, zero)
+        self.assertEqual((b-a)&a, zero)
+        self.assertEqual((a&b)&(a^b), zero)
+
+    def test_cardinality_relations(self):
+        a, b = self.a, self.b
+        self.assertEqual(len(a), len(a-b) + len(a&b))
+        self.assertEqual(len(b), len(b-a) + len(a&b))
+        self.assertEqual(len(a^b), len(a-b) + len(b-a))
+        self.assertEqual(len(a|b), len(a-b) + len(a&b) + len(b-a))
+        self.assertEqual(len(a^b) + len(a&b), len(a|b))
+
+#==============================================================================
+
+libreftest = """
+Example from the Library Reference:  Doc/lib/libsets.tex
+
+>>> from sets import Set as Base  # override _repr to get sorted output
+>>> class Set(Base):
+...     def _repr(self):
+...         return Base._repr(self, sorted=True)
+>>> engineers = Set(['John', 'Jane', 'Jack', 'Janice'])
+>>> programmers = Set(['Jack', 'Sam', 'Susan', 'Janice'])
+>>> managers = Set(['Jane', 'Jack', 'Susan', 'Zack'])
+>>> employees = engineers | programmers | managers           # union
+>>> engineering_management = engineers & managers            # intersection
+>>> fulltime_management = managers - engineers - programmers # difference
+>>> engineers.add('Marvin')
+>>> print engineers
+Set(['Jack', 'Jane', 'Janice', 'John', 'Marvin'])
+>>> employees.issuperset(engineers)           # superset test
+False
+>>> employees.union_update(engineers)         # update from another set
+>>> employees.issuperset(engineers)
+True
+>>> for group in [engineers, programmers, managers, employees]:
+...     group.discard('Susan')                # unconditionally remove element
+...     print group
+...
+Set(['Jack', 'Jane', 'Janice', 'John', 'Marvin'])
+Set(['Jack', 'Janice', 'Sam'])
+Set(['Jack', 'Jane', 'Zack'])
+Set(['Jack', 'Jane', 'Janice', 'John', 'Marvin', 'Sam', 'Zack'])
+"""
+
+#==============================================================================
+
+__test__ = {'libreftest' : libreftest}
+
+def test_main(verbose=None):
+    import doctest
+    from test import test_sets
+    test_support.run_unittest(
+        TestSetOfSets,
+        TestExceptionPropagation,
+        TestBasicOpsEmpty,
+        TestBasicOpsSingleton,
+        TestBasicOpsTuple,
+        TestBasicOpsTriple,
+        TestBinaryOps,
+        TestUpdateOps,
+        TestMutate,
+        TestSubsetEqualEmpty,
+        TestSubsetEqualNonEmpty,
+        TestSubsetEmptyNonEmpty,
+        TestSubsetPartial,
+        TestSubsetNonOverlap,
+        TestOnlySetsNumeric,
+        TestOnlySetsDict,
+        TestOnlySetsOperator,
+        TestOnlySetsTuple,
+        TestOnlySetsString,
+        TestOnlySetsGenerator,
+        TestOnlySetsofSets,
+        TestCopyingEmpty,
+        TestCopyingSingleton,
+        TestCopyingTriple,
+        TestCopyingTuple,
+        TestCopyingNested,
+        TestIdentities,
+        doctest.DocTestSuite(test_sets),
+    )
+
+if __name__ == "__main__":
+    test_main(verbose=True)