Excise the sets module. SF #1500611 by Collin Winter.

5 files changed, 5 insertions, 1437 deletions

diff --git a/Lib/msilib/__init__.py b/Lib/msilib/__init__.py
index 07053ba..9efef91 100644
--- a/Lib/msilib/__init__.py
+++ b/Lib/msilib/__init__.py
@@ -2,7 +2,7 @@
 # Copyright (C) 2005 Martin v. Löwis
 # Licensed to PSF under a Contributor Agreement.
 from _msi import *
-import sets, os, string, re
+import os, string, re
 
 Win64=0
 
@@ -184,7 +184,7 @@ class CAB:
     def __init__(self, name):
         self.name = name
         self.files = []
-        self.filenames = sets.Set()
+        self.filenames = set()
         self.index = 0
 
     def gen_id(self, file):
@@ -215,7 +215,7 @@ class CAB:
         os.unlink(filename)
         db.Commit()
 
-_directories = sets.Set()
+_directories = set()
 class Directory:
     def __init__(self, db, cab, basedir, physical, _logical, default, componentflags=None):
         """Create a new directory in the Directory table. There is a current component
@@ -239,8 +239,8 @@ class Directory:
         self.physical = physical
         self.logical = logical
         self.component = None
-        self.short_names = sets.Set()
-        self.ids = sets.Set()
+        self.short_names = set()
+        self.ids = set()
         self.keyfiles = {}
         self.componentflags = componentflags
         if basedir:
diff --git a/Lib/sets.py b/Lib/sets.py
deleted file mode 100644
index 55f93a6d..0000000
--- a/Lib/sets.py
+++ /dev/null
@@ -1,577 +0,0 @@
-"""Classes to represent arbitrary sets (including sets of sets).
-
-This module implements sets using dictionaries whose values are
-ignored.  The usual operations (union, intersection, deletion, etc.)
-are provided as both methods and operators.
-
-Important: sets are not sequences!  While they support 'x in s',
-'len(s)', and 'for x in s', none of those operations are unique for
-sequences; for example, mappings support all three as well.  The
-characteristic operation for sequences is subscripting with small
-integers: s[i], for i in range(len(s)).  Sets don't support
-subscripting at all.  Also, sequences allow multiple occurrences and
-their elements have a definite order; sets on the other hand don't
-record multiple occurrences and don't remember the order of element
-insertion (which is why they don't support s[i]).
-
-The following classes are provided:
-
-BaseSet -- All the operations common to both mutable and immutable
-    sets. This is an abstract class, not meant to be directly
-    instantiated.
-
-Set -- Mutable sets, subclass of BaseSet; not hashable.
-
-ImmutableSet -- Immutable sets, subclass of BaseSet; hashable.
-    An iterable argument is mandatory to create an ImmutableSet.
-
-_TemporarilyImmutableSet -- A wrapper around a Set, hashable,
-    giving the same hash value as the immutable set equivalent
-    would have.  Do not use this class directly.
-
-Only hashable objects can be added to a Set. In particular, you cannot
-really add a Set as an element to another Set; if you try, what is
-actually added is an ImmutableSet built from it (it compares equal to
-the one you tried adding).
-
-When you ask if `x in y' where x is a Set and y is a Set or
-ImmutableSet, x is wrapped into a _TemporarilyImmutableSet z, and
-what's tested is actually `z in y'.
-
-"""
-
-# Code history:
-#
-# - Greg V. Wilson wrote the first version, using a different approach
-#   to the mutable/immutable problem, and inheriting from dict.
-#
-# - Alex Martelli modified Greg's version to implement the current
-#   Set/ImmutableSet approach, and make the data an attribute.
-#
-# - Guido van Rossum rewrote much of the code, made some API changes,
-#   and cleaned up the docstrings.
-#
-# - Raymond Hettinger added a number of speedups and other
-#   improvements.
-
-from __future__ import generators
-try:
-    from itertools import ifilter, ifilterfalse
-except ImportError:
-    # Code to make the module run under Py2.2
-    def ifilter(predicate, iterable):
-        if predicate is None:
-            def predicate(x):
-                return x
-        for x in iterable:
-            if predicate(x):
-                yield x
-    def ifilterfalse(predicate, iterable):
-        if predicate is None:
-            def predicate(x):
-                return x
-        for x in iterable:
-            if not predicate(x):
-                yield x
-    try:
-        True, False
-    except NameError:
-        True, False = (0==0, 0!=0)
-
-__all__ = ['BaseSet', 'Set', 'ImmutableSet']
-
-class BaseSet(object):
-    """Common base class for mutable and immutable sets."""
-
-    __slots__ = ['_data']
-
-    # Constructor
-
-    def __init__(self):
-        """This is an abstract class."""
-        # Don't call this from a concrete subclass!
-        if self.__class__ is BaseSet:
-            raise TypeError, ("BaseSet is an abstract class.  "
-                              "Use Set or ImmutableSet.")
-
-    # Standard protocols: __len__, __repr__, __str__, __iter__
-
-    def __len__(self):
-        """Return the number of elements of a set."""
-        return len(self._data)
-
-    def __repr__(self):
-        """Return string representation of a set.
-
-        This looks like 'Set([<list of elements>])'.
-        """
-        return self._repr()
-
-    # __str__ is the same as __repr__
-    __str__ = __repr__
-
-    def _repr(self, sorted=False):
-        elements = self._data.keys()
-        if sorted:
-            elements.sort()
-        return '%s(%r)' % (self.__class__.__name__, elements)
-
-    def __iter__(self):
-        """Return an iterator over the elements or a set.
-
-        This is the keys iterator for the underlying dict.
-        """
-        return self._data.iterkeys()
-
-    # Three-way comparison is not supported.  However, because __eq__ is
-    # tried before __cmp__, if Set x == Set y, x.__eq__(y) returns True and
-    # then cmp(x, y) returns 0 (Python doesn't actually call __cmp__ in this
-    # case).
-
-    def __cmp__(self, other):
-        raise TypeError, "can't compare sets using cmp()"
-
-    # Equality comparisons using the underlying dicts.  Mixed-type comparisons
-    # are allowed here, where Set == z for non-Set z always returns False,
-    # and Set != z always True.  This allows expressions like "x in y" to
-    # give the expected result when y is a sequence of mixed types, not
-    # raising a pointless TypeError just because y contains a Set, or x is
-    # a Set and y contain's a non-set ("in" invokes only __eq__).
-    # Subtle:  it would be nicer if __eq__ and __ne__ could return
-    # NotImplemented instead of True or False.  Then the other comparand
-    # would get a chance to determine the result, and if the other comparand
-    # also returned NotImplemented then it would fall back to object address
-    # comparison (which would always return False for __eq__ and always
-    # True for __ne__).  However, that doesn't work, because this type
-    # *also* implements __cmp__:  if, e.g., __eq__ returns NotImplemented,
-    # Python tries __cmp__ next, and the __cmp__ here then raises TypeError.
-
-    def __eq__(self, other):
-        if isinstance(other, BaseSet):
-            return self._data == other._data
-        else:
-            return False
-
-    def __ne__(self, other):
-        if isinstance(other, BaseSet):
-            return self._data != other._data
-        else:
-            return True
-
-    # Copying operations
-
-    def copy(self):
-        """Return a shallow copy of a set."""
-        result = self.__class__()
-        result._data.update(self._data)
-        return result
-
-    __copy__ = copy # For the copy module
-
-    def __deepcopy__(self, memo):
-        """Return a deep copy of a set; used by copy module."""
-        # This pre-creates the result and inserts it in the memo
-        # early, in case the deep copy recurses into another reference
-        # to this same set.  A set can't be an element of itself, but
-        # it can certainly contain an object that has a reference to
-        # itself.
-        from copy import deepcopy
-        result = self.__class__()
-        memo[id(self)] = result
-        data = result._data
-        value = True
-        for elt in self:
-            data[deepcopy(elt, memo)] = value
-        return result
-
-    # Standard set operations: union, intersection, both differences.
-    # Each has an operator version (e.g. __or__, invoked with |) and a
-    # method version (e.g. union).
-    # Subtle:  Each pair requires distinct code so that the outcome is
-    # correct when the type of other isn't suitable.  For example, if
-    # we did "union = __or__" instead, then Set().union(3) would return
-    # NotImplemented instead of raising TypeError (albeit that *why* it
-    # raises TypeError as-is is also a bit subtle).
-
-    def __or__(self, other):
-        """Return the union of two sets as a new set.
-
-        (I.e. all elements that are in either set.)
-        """
-        if not isinstance(other, BaseSet):
-            return NotImplemented
-        return self.union(other)
-
-    def union(self, other):
-        """Return the union of two sets as a new set.
-
-        (I.e. all elements that are in either set.)
-        """
-        result = self.__class__(self)
-        result._update(other)
-        return result
-
-    def __and__(self, other):
-        """Return the intersection of two sets as a new set.
-
-        (I.e. all elements that are in both sets.)
-        """
-        if not isinstance(other, BaseSet):
-            return NotImplemented
-        return self.intersection(other)
-
-    def intersection(self, other):
-        """Return the intersection of two sets as a new set.
-
-        (I.e. all elements that are in both sets.)
-        """
-        if not isinstance(other, BaseSet):
-            other = Set(other)
-        if len(self) <= len(other):
-            little, big = self, other
-        else:
-            little, big = other, self
-        common = ifilter(big._data.__contains__, little)
-        return self.__class__(common)
-
-    def __xor__(self, other):
-        """Return the symmetric difference of two sets as a new set.
-
-        (I.e. all elements that are in exactly one of the sets.)
-        """
-        if not isinstance(other, BaseSet):
-            return NotImplemented
-        return self.symmetric_difference(other)
-
-    def symmetric_difference(self, other):
-        """Return the symmetric difference of two sets as a new set.
-
-        (I.e. all elements that are in exactly one of the sets.)
-        """
-        result = self.__class__()
-        data = result._data
-        value = True
-        selfdata = self._data
-        try:
-            otherdata = other._data
-        except AttributeError:
-            otherdata = Set(other)._data
-        for elt in ifilterfalse(otherdata.__contains__, selfdata):
-            data[elt] = value
-        for elt in ifilterfalse(selfdata.__contains__, otherdata):
-            data[elt] = value
-        return result
-
-    def  __sub__(self, other):
-        """Return the difference of two sets as a new Set.
-
-        (I.e. all elements that are in this set and not in the other.)
-        """
-        if not isinstance(other, BaseSet):
-            return NotImplemented
-        return self.difference(other)
-
-    def difference(self, other):
-        """Return the difference of two sets as a new Set.
-
-        (I.e. all elements that are in this set and not in the other.)
-        """
-        result = self.__class__()
-        data = result._data
-        try:
-            otherdata = other._data
-        except AttributeError:
-            otherdata = Set(other)._data
-        value = True
-        for elt in ifilterfalse(otherdata.__contains__, self):
-            data[elt] = value
-        return result
-
-    # Membership test
-
-    def __contains__(self, element):
-        """Report whether an element is a member of a set.
-
-        (Called in response to the expression `element in self'.)
-        """
-        try:
-            return element in self._data
-        except TypeError:
-            transform = getattr(element, "__as_temporarily_immutable__", None)
-            if transform is None:
-                raise # re-raise the TypeError exception we caught
-            return transform() in self._data
-
-    # Subset and superset test
-
-    def issubset(self, other):
-        """Report whether another set contains this set."""
-        self._binary_sanity_check(other)
-        if len(self) > len(other):  # Fast check for obvious cases
-            return False
-        for elt in ifilterfalse(other._data.__contains__, self):
-            return False
-        return True
-
-    def issuperset(self, other):
-        """Report whether this set contains another set."""
-        self._binary_sanity_check(other)
-        if len(self) < len(other):  # Fast check for obvious cases
-            return False
-        for elt in ifilterfalse(self._data.__contains__, other):
-            return False
-        return True
-
-    # Inequality comparisons using the is-subset relation.
-    __le__ = issubset
-    __ge__ = issuperset
-
-    def __lt__(self, other):
-        self._binary_sanity_check(other)
-        return len(self) < len(other) and self.issubset(other)
-
-    def __gt__(self, other):
-        self._binary_sanity_check(other)
-        return len(self) > len(other) and self.issuperset(other)
-
-    # Assorted helpers
-
-    def _binary_sanity_check(self, other):
-        # Check that the other argument to a binary operation is also
-        # a set, raising a TypeError otherwise.
-        if not isinstance(other, BaseSet):
-            raise TypeError, "Binary operation only permitted between sets"
-
-    def _compute_hash(self):
-        # Calculate hash code for a set by xor'ing the hash codes of
-        # the elements.  This ensures that the hash code does not depend
-        # on the order in which elements are added to the set.  This is
-        # not called __hash__ because a BaseSet should not be hashable;
-        # only an ImmutableSet is hashable.
-        result = 0
-        for elt in self:
-            result ^= hash(elt)
-        return result
-
-    def _update(self, iterable):
-        # The main loop for update() and the subclass __init__() methods.
-        data = self._data
-
-        # Use the fast update() method when a dictionary is available.
-        if isinstance(iterable, BaseSet):
-            data.update(iterable._data)
-            return
-
-        value = True
-
-        if type(iterable) in (list, tuple, xrange):
-            # Optimized: we know that __iter__() and next() can't
-            # raise TypeError, so we can move 'try:' out of the loop.
-            it = iter(iterable)
-            while True:
-                try:
-                    for element in it:
-                        data[element] = value
-                    return
-                except TypeError:
-                    transform = getattr(element, "__as_immutable__", None)
-                    if transform is None:
-                        raise # re-raise the TypeError exception we caught
-                    data[transform()] = value
-        else:
-            # Safe: only catch TypeError where intended
-            for element in iterable:
-                try:
-                    data[element] = value
-                except TypeError:
-                    transform = getattr(element, "__as_immutable__", None)
-                    if transform is None:
-                        raise # re-raise the TypeError exception we caught
-                    data[transform()] = value
-
-
-class ImmutableSet(BaseSet):
-    """Immutable set class."""
-
-    __slots__ = ['_hashcode']
-
-    # BaseSet + hashing
-
-    def __init__(self, iterable=None):
-        """Construct an immutable set from an optional iterable."""
-        self._hashcode = None
-        self._data = {}
-        if iterable is not None:
-            self._update(iterable)
-
-    def __hash__(self):
-        if self._hashcode is None:
-            self._hashcode = self._compute_hash()
-        return self._hashcode
-
-    def __getstate__(self):
-        return self._data, self._hashcode
-
-    def __setstate__(self, state):
-        self._data, self._hashcode = state
-
-class Set(BaseSet):
-    """ Mutable set class."""
-
-    __slots__ = []
-
-    # BaseSet + operations requiring mutability; no hashing
-
-    def __init__(self, iterable=None):
-        """Construct a set from an optional iterable."""
-        self._data = {}
-        if iterable is not None:
-            self._update(iterable)
-
-    def __getstate__(self):
-        # getstate's results are ignored if it is not
-        return self._data,
-
-    def __setstate__(self, data):
-        self._data, = data
-
-    def __hash__(self):
-        """A Set cannot be hashed."""
-        # We inherit object.__hash__, so we must deny this explicitly
-        raise TypeError, "Can't hash a Set, only an ImmutableSet."
-
-    # In-place union, intersection, differences.
-    # Subtle:  The xyz_update() functions deliberately return None,
-    # as do all mutating operations on built-in container types.
-    # The __xyz__ spellings have to return self, though.
-
-    def __ior__(self, other):
-        """Update a set with the union of itself and another."""
-        self._binary_sanity_check(other)
-        self._data.update(other._data)
-        return self
-
-    def union_update(self, other):
-        """Update a set with the union of itself and another."""
-        self._update(other)
-
-    def __iand__(self, other):
-        """Update a set with the intersection of itself and another."""
-        self._binary_sanity_check(other)
-        self._data = (self & other)._data
-        return self
-
-    def intersection_update(self, other):
-        """Update a set with the intersection of itself and another."""
-        if isinstance(other, BaseSet):
-            self &= other
-        else:
-            self._data = (self.intersection(other))._data
-
-    def __ixor__(self, other):
-        """Update a set with the symmetric difference of itself and another."""
-        self._binary_sanity_check(other)
-        self.symmetric_difference_update(other)
-        return self
-
-    def symmetric_difference_update(self, other):
-        """Update a set with the symmetric difference of itself and another."""
-        data = self._data
-        value = True
-        if not isinstance(other, BaseSet):
-            other = Set(other)
-        if self is other:
-            self.clear()
-        for elt in other:
-            if elt in data:
-                del data[elt]
-            else:
-                data[elt] = value
-
-    def __isub__(self, other):
-        """Remove all elements of another set from this set."""
-        self._binary_sanity_check(other)
-        self.difference_update(other)
-        return self
-
-    def difference_update(self, other):
-        """Remove all elements of another set from this set."""
-        data = self._data
-        if not isinstance(other, BaseSet):
-            other = Set(other)
-        if self is other:
-            self.clear()
-        for elt in ifilter(data.__contains__, other):
-            del data[elt]
-
-    # Python dict-like mass mutations: update, clear
-
-    def update(self, iterable):
-        """Add all values from an iterable (such as a list or file)."""
-        self._update(iterable)
-
-    def clear(self):
-        """Remove all elements from this set."""
-        self._data.clear()
-
-    # Single-element mutations: add, remove, discard
-
-    def add(self, element):
-        """Add an element to a set.
-
-        This has no effect if the element is already present.
-        """
-        try:
-            self._data[element] = True
-        except TypeError:
-            transform = getattr(element, "__as_immutable__", None)
-            if transform is None:
-                raise # re-raise the TypeError exception we caught
-            self._data[transform()] = True
-
-    def remove(self, element):
-        """Remove an element from a set; it must be a member.
-
-        If the element is not a member, raise a KeyError.
-        """
-        try:
-            del self._data[element]
-        except TypeError:
-            transform = getattr(element, "__as_temporarily_immutable__", None)
-            if transform is None:
-                raise # re-raise the TypeError exception we caught
-            del self._data[transform()]
-
-    def discard(self, element):
-        """Remove an element from a set if it is a member.
-
-        If the element is not a member, do nothing.
-        """
-        try:
-            self.remove(element)
-        except KeyError:
-            pass
-
-    def pop(self):
-        """Remove and return an arbitrary set element."""
-        return self._data.popitem()[0]
-
-    def __as_immutable__(self):
-        # Return a copy of self as an immutable set
-        return ImmutableSet(self)
-
-    def __as_temporarily_immutable__(self):
-        # Return self wrapped in a temporarily immutable set
-        return _TemporarilyImmutableSet(self)
-
-
-class _TemporarilyImmutableSet(BaseSet):
-    # Wrap a mutable set as if it was temporarily immutable.
-    # This only supplies hashing and equality comparisons.
-
-    def __init__(self, set):
-        self._set = set
-        self._data = set._data  # Needed by ImmutableSet.__eq__()
-
-    def __hash__(self):
-        return self._set._compute_hash()
diff --git a/Lib/test/test_cookielib.py b/Lib/test/test_cookielib.py
index 991506c..544f29f 100644
--- a/Lib/test/test_cookielib.py
+++ b/Lib/test/test_cookielib.py
@@ -1723,7 +1723,6 @@ class LWPCookieTests(TestCase):
 
 
 def test_main(verbose=None):
-    from test import test_sets
     test_support.run_unittest(
         DateTimeTests,
         HeaderTests,
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 6641ff8..9bd0d43 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -1451,7 +1451,6 @@ class TestVariousIteratorArgs(unittest.TestCase):
 #==============================================================================
 
 def test_main(verbose=None):
-    from test import test_sets
     test_classes = (
         TestSet,
         TestSetSubclass,
diff --git a/Lib/test/test_sets.py b/Lib/test/test_sets.py
deleted file mode 100644
index 88cfcac..0000000
--- a/Lib/test/test_sets.py
+++ /dev/null
@@ -1,853 +0,0 @@
-#!/usr/bin/env python
-
-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)
-
-        # In py3k, this works!
-        self.assertRaises(TypeError, cmp, a, a)
-
-        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 = sorted(dup, key=repr)
-        set_list = sorted(self.set, key=repr)
-        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 = sorted(dup, key=repr)
-        set_list = sorted(self.set, key=repr)
-        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)