testBTrees.py

##############################################################################
#
# Copyright (c) 2001, 2002 Zope Corporation and Contributors.
# All Rights Reserved.
# 
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
# 
##############################################################################
import sys, os, time, random
import os, sys

from BTrees.OOBTree import OOBTree, OOBucket, OOSet, OOTreeSet
from BTrees.IOBTree import IOBTree, IOBucket, IOSet, IOTreeSet
from BTrees.IIBTree import IIBTree, IIBucket, IISet, IITreeSet
from BTrees.OIBTree import OIBTree, OIBucket, OISet, OITreeSet
from unittest import TestCase, TestSuite, TextTestRunner, makeSuite

from glob import glob

class Base:
    """ Tests common to all types: sets, buckets, and BTrees """
    def tearDown(self):
        self.t = None
        del self.t

    def _getRoot(self):
        from ZODB.FileStorage import FileStorage
        from ZODB.DB import DB
        n = 'fs_tmp__%s' % os.getpid()
        s = FileStorage(n)
        db = DB(s)
        root = db.open().root()
        return root

    def _closeDB(self, root):
        if root is not None:
            root._p_jar._db.close()

    def _delDB(self):
        for file in glob('fs_tmp__*'):
            os.remove(file)
        
    def testLoadAndStore(self):
        for i in 0, 10, 1000:
            t = self.t.__class__()
            self._populate(t, i)
            root = None
            try:
                root = self._getRoot()
                root[i] = t
                get_transaction().commit()
            except:
                self._closeDB(root)
                self._delDB()
                raise

            self._closeDB(root)

            root = None
            try:
                root = self._getRoot()
                #XXX BTree stuff doesn't implement comparison
                if hasattr(t, 'items'):
                    self.assertEqual(list(root[i].items()) , list(t.items()))
                else:
                    self.assertEqual(list(root[i].keys()) , list(t.keys()))
            finally:
                self._closeDB(root)
                self._delDB()
            
    def testGhostUnghost(self):
        for i in 0, 10, 1000:
            t = self.t.__class__()
            self._populate(t, i)
            root = None
            try:
                root = self._getRoot()
                root[i] = t
                get_transaction().commit()
            except:
                self._closeDB(root)
                self._delDB()
                raise

            self._closeDB(root)

            root = None
            try:
                root = self._getRoot()
                root[i]._p_changed = None
                get_transaction().commit()
                if hasattr(t,'items'):
                    self.assertEqual(list(root[i].items()) , list(t.items()))
                else:
                    self.assertEqual(list(root[i].keys()) , list(t.keys()))
            finally:
                self._closeDB(root)
                self._delDB()

class MappingBase(Base):
    """ Tests common to mappings (buckets, btrees) """

    def _populate(self, t, l):
        # Make some data
        for i in range(l): t[i]=i
    
    def testGetItemFails(self):
        self.assertRaises(KeyError, self._getitemfail)

    def _getitemfail(self):
        return self.t[1]

    def testGetReturnsDefault(self):
        self.assertEqual(self.t.get(1) , None)
        self.assertEqual(self.t.get(1, 'foo') , 'foo')
        
    def testSetItemGetItemWorks(self):
        self.t[1] = 1
        a = self.t[1]
        self.assertEqual(a , 1, `a`)

    def testReplaceWorks(self):
        self.t[1] = 1
        self.assertEqual(self.t[1] , 1, self.t[1])
        self.t[1] = 2
        self.assertEqual(self.t[1] , 2, self.t[1])

    def testLen(self):
        added = {}
        r = range(1000)
        for x in r:
            k = random.choice(r)
            self.t[k] = x
            added[k] = x
        addl = added.keys()
        self.assertEqual(len(self.t) , len(addl), len(self.t))

    def testHasKeyWorks(self):
        self.t[1] = 1
        self.assert_(self.t.has_key(1))

    def testValuesWorks(self):
        for x in range(100):
            self.t[x] = x*x
        v = self.t.values()
        for i in range(100):
            self.assertEqual(v[i],i*i , (i*i,i))

    def testValuesWorks1(self):

        for x in range(100):
            self.t[99-x] = x 

        for x in range(40):
            lst = list(self.t.values(0+x,99-x))
            lst.sort()
            self.assertEqual(lst,range(0+x,99-x+1))

            
    def testKeysWorks(self):
        for x in range(100):
            self.t[x] = x
        v = self.t.keys()
        i = 0
        for x in v:
            self.assertEqual(x,i)
            i = i + 1

        for x in range(40):
            lst = self.t.keys(0+x,99-x)
            self.assertEqual(list(lst),range(0+x,99-x+1))

        # BTree items must lie about their lengths, so we convert to list
        self.assertEqual(len(v) , 100, len(v))
        #self.assertEqual(len(v) , 100, len(v))

    def testItemsWorks(self):
        for x in range(100):
            self.t[x] = x
        v = self.t.items()
        i = 0
        for x in v:
            self.assertEqual(x[0] , i, (x[0], i))
            self.assertEqual(x[1] , i, (x[0], i))
            i = i + 1

    def testDeleteInvalidKeyRaisesKeyError(self):
        self.assertRaises(KeyError, self._deletefail)

    def _deletefail(self):
        del self.t[1]

    def testMaxKeyMinKey(self):
        self.t[7] = 6
        self.t[3] = 10
        self.t[8] = 12
        self.t[1] = 100
        self.t[5] = 200
        self.t[10] = 500
        self.t[6] = 99
        self.t[4] = 150
        del self.t[7]
        t = self.t
        self.assertEqual(t.maxKey() , 10)
        self.assertEqual(t.maxKey(6) , 6)
        self.assertEqual(t.maxKey(9) , 8)
        self.assertEqual(t.minKey() , 1)
        self.assertEqual(t.minKey(3) , 3)
        self.assertEqual(t.minKey(9) , 10)

    def testClear(self):
        r = range(100)
        for x in r:
            rnd = random.choice(r)
            self.t[rnd] = 0
        self.t.clear()
        diff = lsubtract(list(self.t.keys()), [])
        self.assertEqual(diff , [], diff)

    def testUpdate(self):
        "mapping update"
        d={}
        l=[]
        for i in range(10000):
            k=random.randrange(-2000, 2001)
            d[k]=i
            l.append((k, i))
            
        items=d.items()
        items.sort()

        self.t.update(d)
        self.assertEqual(list(self.t.items()) , items)

        self.t.clear()
        self.assertEqual(list(self.t.items()) , [])

        self.t.update(l)
        self.assertEqual(list(self.t.items()) , items)

    def testEmptyRangeSearches(self):
        t=self.t
        t.update([(1,1),(5,5),(9,9)])
        self.assertEqual(list(t.keys(-6,-4)),[], list(t.keys(-6,-4)))
        self.assertEqual(list(t.keys(2,4)),[], list(t.keys(2,4)))
        self.assertEqual(list(t.keys(6,8)),[], list(t.keys(6,8)))
        self.assertEqual(list(t.keys(10,12)),[], list(t.keys(10,12)))
        

class NormalSetTests(Base):
    """ Test common to all set types """


    def _populate(self, t, l): 
        # Make some data
        t.update(range(l))


    def testInsertReturnsValue(self):
        t = self.t
        self.assertEqual(t.insert(5) , 1)

    def testDuplicateInsert(self):
        t = self.t
        t.insert(5)
        self.assertEqual(t.insert(5) , 0)
        
    def testInsert(self):
        t = self.t
        t.insert(1)
        self.assert_(t.has_key(1))

    def testBigInsert(self):
        t = self.t
        r = xrange(10000)
        for x in r:
            t.insert(x)
        for x in r:
            self.assert_(t.has_key(x))

    def testRemoveSucceeds(self):
        t = self.t
        r = xrange(10000)
        for x in r: t.insert(x)
        for x in r: t.remove(x)

    def testRemoveFails(self):
        self.assertRaises(KeyError, self._removenonexistent)

    def _removenonexistent(self):
        self.t.remove(1)

    def testHasKeyFails(self):
        t = self.t
        self.assert_(not t.has_key(1))

    def testKeys(self):
        t = self.t
        r = xrange(1000)
        for x in r: t.insert(x)
        diff = lsubtract(t.keys(), r)
        self.assertEqual(diff , [], diff)

    def testClear(self):
        t = self.t
        r = xrange(1000)
        for x in r: t.insert(x)
        t.clear()
        diff = lsubtract(t.keys(), [])
        self.assertEqual(diff , [], diff)

    def testMaxKeyMinKey(self):
        t = self.t
        t.insert(1)
        t.insert(2)
        t.insert(3)
        t.insert(8)
        t.insert(5)
        t.insert(10)
        t.insert(6)
        t.insert(4)
        self.assertEqual(t.maxKey() , 10)
        self.assertEqual(t.maxKey(6) , 6)
        self.assertEqual(t.maxKey(9) , 8)
        self.assertEqual(t.minKey() , 1)
        self.assertEqual(t.minKey(3) , 3)
        self.assertEqual(t.minKey(9) , 10)

    def testUpdate(self):
        "mapping update"
        d={}
        l=[]
        for i in range(10000):
            k=random.randrange(-2000, 2001)
            d[k]=i
            l.append(k)
            
        items=d.keys()
        items.sort()

        self.t.update(l)
        self.assertEqual(list(self.t.keys()) , items)

    def testEmptyRangeSearches(self):
        t=self.t
        t.update([1,5,9])
        self.assertEqual(list(t.keys(-6,-4)),[], list(t.keys(-6,-4)))
        self.assertEqual(list(t.keys(2,4)),[], list(t.keys(2,4)))
        self.assertEqual(list(t.keys(6,8)),[], list(t.keys(6,8)))
        self.assertEqual(list(t.keys(10,12)),[], list(t.keys(10,12)))

class ExtendedSetTests(NormalSetTests):
    def testLen(self):
        t = self.t
        r = xrange(10000)
        for x in r: t.insert(x)
        self.assertEqual(len(t) , 10000, len(t))

    def testGetItem(self):
        t = self.t
        r = xrange(10000)
        for x in r: t.insert(x)
        for x in r:
            self.assertEqual(t[x] , x)
        
class BucketTests(MappingBase):
    """ Tests common to all buckets """
    pass

class BTreeTests(MappingBase):
    """ Tests common to all BTrees """
    def testDeleteNoChildrenWorks(self):
        self.t[5] = 6
        self.t[2] = 10
        self.t[6] = 12
        self.t[1] = 100
        self.t[3] = 200
        self.t[10] = 500
        self.t[4] = 99
        del self.t[4]
        diff = lsubtract(self.t.keys(), [1,2,3,5,6,10])
        self.assertEqual(diff , [], diff)

    def testDeleteOneChildWorks(self):
        self.t[5] = 6
        self.t[2] = 10
        self.t[6] = 12
        self.t[1] = 100
        self.t[3] = 200
        self.t[10] = 500
        self.t[4] = 99
        del self.t[3]
        diff = lsubtract(self.t.keys(), [1,2,4,5,6,10])
        self.assertEqual(diff , [], diff)

    def testDeleteTwoChildrenNoInorderSuccessorWorks(self):
        self.t[5] = 6
        self.t[2] = 10
        self.t[6] = 12
        self.t[1] = 100
        self.t[3] = 200
        self.t[10] = 500
        self.t[4] = 99
        del self.t[2]
        diff = lsubtract(self.t.keys(), [1,3,4,5,6,10])
        self.assertEqual(diff , [], diff)
        
    def testDeleteTwoChildrenInorderSuccessorWorks(self):
        """ 7, 3, 8, 1, 5, 10, 6, 4 -- del 3 """
        self.t[7] = 6
        self.t[3] = 10
        self.t[8] = 12
        self.t[1] = 100
        self.t[5] = 200
        self.t[10] = 500
        self.t[6] = 99
        self.t[4] = 150
        del self.t[3]
        diff = lsubtract(self.t.keys(), [1,4,5,6,7,8,10])
        self.assertEqual(diff , [], diff)

    def testDeleteRootWorks(self):
        """ 7, 3, 8, 1, 5, 10, 6, 4 -- del 7 """
        self.t[7] = 6
        self.t[3] = 10
        self.t[8] = 12
        self.t[1] = 100
        self.t[5] = 200
        self.t[10] = 500
        self.t[6] = 99
        self.t[4] = 150
        del self.t[7]
        diff = lsubtract(self.t.keys(), [1,3,4,5,6,8,10])
        self.assertEqual(diff , [], diff)

    def testRandomNonOverlappingInserts(self):
        added = {}
        r = range(100)
        for x in r:
            k = random.choice(r)
            if not added.has_key(k):
                self.t[k] = x
                added[k] = 1
        addl = added.keys()
        addl.sort()
        diff = lsubtract(list(self.t.keys()), addl)
        self.assertEqual(diff , [], (diff, addl, list(self.t.keys())))

    def testRandomOverlappingInserts(self):
        added = {}
        r = range(100)
        for x in r:
            k = random.choice(r)
            self.t[k] = x
            added[k] = 1
        addl = added.keys()
        addl.sort()
        diff = lsubtract(self.t.keys(), addl)
        self.assertEqual(diff , [], diff)

    def testRandomDeletes(self):
        r = range(1000)
        added = []
        for x in r:
            k = random.choice(r)
            self.t[k] = x
            added.append(k)
        deleted = []
        for x in r:
            k = random.choice(r)
            if self.t.has_key(k):
                del self.t[k]
                deleted.append(k)
                if self.t.has_key(k):
                    raise "had problems deleting %s" % k
        badones = []
        for x in deleted:
            if self.t.has_key(x):
                badones.append(x)
        self.assertEqual(badones , [], (badones, added, deleted))

    def testTargetedDeletes(self):
        r = range(1000)
        for x in r:
            k = random.choice(r)
            self.t[k] = x
        for x in r:
            try:
                del self.t[x]
            except KeyError:
                pass
        self.assertEqual(realseq(self.t.keys()) , [], realseq(self.t.keys()))
        
    def testPathologicalRightBranching(self):
        r = range(1000)
        for x in r:
            self.t[x] = 1
        self.assertEqual(realseq(self.t.keys()) , r, realseq(self.t.keys()))
        for x in r:
            del self.t[x]
        self.assertEqual(realseq(self.t.keys()) , [], realseq(self.t.keys()))

    def testPathologicalLeftBranching(self):
        r = range(1000)
        revr = r[:]
        revr.reverse()
        for x in revr:
            self.t[x] = 1
        self.assertEqual(realseq(self.t.keys()) , r, realseq(self.t.keys()))

        for x in revr:
            del self.t[x]
        self.assertEqual(realseq(self.t.keys()) , [], realseq(self.t.keys()))

    def testSuccessorChildParentRewriteExerciseCase(self):
        add_order = [
            85, 73, 165, 273, 215, 142, 233, 67, 86, 166, 235, 225, 255,
            73, 175, 171, 285, 162, 108, 28, 283, 258, 232, 199, 260,
            298, 275, 44, 261, 291, 4, 181, 285, 289, 216, 212, 129,
            243, 97, 48, 48, 159, 22, 285, 92, 110, 27, 55, 202, 294,
            113, 251, 193, 290, 55, 58, 239, 71, 4, 75, 129, 91, 111,
            271, 101, 289, 194, 218, 77, 142, 94, 100, 115, 101, 226,
            17, 94, 56, 18, 163, 93, 199, 286, 213, 126, 240, 245, 190,
            195, 204, 100, 199, 161, 292, 202, 48, 165, 6, 173, 40, 218,
            271, 228, 7, 166, 173, 138, 93, 22, 140, 41, 234, 17, 249,
            215, 12, 292, 246, 272, 260, 140, 58, 2, 91, 246, 189, 116,
            72, 259, 34, 120, 263, 168, 298, 118, 18, 28, 299, 192, 252,
            112, 60, 277, 273, 286, 15, 263, 141, 241, 172, 255, 52, 89,
            127, 119, 255, 184, 213, 44, 116, 231, 173, 298, 178, 196,
            89, 184, 289, 98, 216, 115, 35, 132, 278, 238, 20, 241, 128,
            179, 159, 107, 206, 194, 31, 260, 122, 56, 144, 118, 283,
            183, 215, 214, 87, 33, 205, 183, 212, 221, 216, 296, 40,
            108, 45, 188, 139, 38, 256, 276, 114, 270, 112, 214, 191,
            147, 111, 299, 107, 101, 43, 84, 127, 67, 205, 251, 38, 91,
            297, 26, 165, 187, 19, 6, 73, 4, 176, 195, 90, 71, 30, 82,
            139, 210, 8, 41, 253, 127, 190, 102, 280, 26, 233, 32, 257,
            194, 263, 203, 190, 111, 218, 199, 29, 81, 207, 18, 180,
            157, 172, 192, 135, 163, 275, 74, 296, 298, 265, 105, 191,
            282, 277, 83, 188, 144, 259, 6, 173, 81, 107, 292, 231,
            129, 65, 161, 113, 103, 136, 255, 285, 289, 1
            ]
        delete_order = [
            276, 273, 12, 275, 2, 286, 127, 83, 92, 33, 101, 195,
            299, 191, 22, 232, 291, 226, 110, 94, 257, 233, 215, 184,
            35, 178, 18, 74, 296, 210, 298, 81, 265, 175, 116, 261,
            212, 277, 260, 234, 6, 129, 31, 4, 235, 249, 34, 289, 105,
            259, 91, 93, 119, 7, 183, 240, 41, 253, 290, 136, 75, 292,
            67, 112, 111, 256, 163, 38, 126, 139, 98, 56, 282, 60, 26,
            55, 245, 225, 32, 52, 40, 271, 29, 252, 239, 89, 87, 205,
            213, 180, 97, 108, 120, 218, 44, 187, 196, 251, 202, 203,
            172, 28, 188, 77, 90, 199, 297, 282, 141, 100, 161, 216,
            73, 19, 17, 189, 30, 258
            ]
        for x in add_order:
            self.t[x] = 1
        for x in delete_order:
            try: del self.t[x]
            except KeyError:
                if self.t.has_key(x): self.assertEqual(1,2,"failed to delete %s" % x)

    def testRangeSearchAfterSequentialInsert(self):
        r = range(100)
        for x in r:
            self.t[x] = 0
        diff = lsubtract(list(self.t.keys(0, 100)), r)
        self.assertEqual(diff , [], diff)

    def testRangeSearchAfterRandomInsert(self):
        r = range(100)
        a = {}
        for x in r:
            rnd = random.choice(r)
            self.t[rnd] = 0
            a[rnd] = 0
        diff = lsubtract(list(self.t.keys(0, 100)), a.keys())
        self.assertEqual(diff , [], diff)

    def testInsertMethod(self):
        t = self.t
        t[0] = 1
        self.assertEqual(t.insert(0, 1) , 0)
        self.assertEqual(t.insert(1, 1) , 1)
        self.assertEqual(lsubtract(list(t.keys()), [0,1]) , [])

## BTree tests

class TestIOBTrees(BTreeTests, TestCase):
    def setUp(self):
        self.t = IOBTree()

    def nonIntegerKeyRaises(self):
        self.assertRaises(TypeError, self._stringraises)
        self.assertRaises(TypeError, self._floatraises)
        self.assertRaises(TypeError, self._noneraises)

    def _stringraises(self):
        self.t['c'] = 1

    def _floatraises(self):
        self.t[2.5] = 1

    def _noneraises(self):
        self.t[None] = 1

    def testEmptyFirstBucketReportedByGuido(self):
        b = self.t
        for i in xrange(29972): # reduce to 29971 and it works
            b[i] = i
        for i in xrange(30): # reduce to 29 and it works
            del b[i]
            b[i+40000] = i

        self.assertEqual(b.keys()[0], 30)

class TestOOBTrees(BTreeTests, TestCase):
    def setUp(self):
        self.t = OOBTree()

class TestOIBTrees(BTreeTests, TestCase):
    def setUp(self):
        self.t = OIBTree()

    def testNonIntegerValueRaises(self):
        self.assertRaises(TypeError, self._stringraises)
        self.assertRaises(TypeError, self._floatraises)
        self.assertRaises(TypeError, self._noneraises)

    def _stringraises(self):
        self.t[1] = 'c'

    def _floatraises(self):
        self.t[1] = 1.4

    def _noneraises(self):
        self.t[1] = None

class TestIIBTrees(BTreeTests, TestCase):
    def setUp(self):
        self.t = IIBTree()

    def testNonIntegerKeyRaises(self):
        self.assertRaises(TypeError, self._stringraiseskey)
        self.assertRaises(TypeError, self._floatraiseskey)
        self.assertRaises(TypeError, self._noneraiseskey)

    def testNonIntegerValueRaises(self):
        self.assertRaises(TypeError, self._stringraisesvalue)
        self.assertRaises(TypeError, self._floatraisesvalue)
        self.assertRaises(TypeError, self._noneraisesvalue)

    def _stringraiseskey(self):
        self.t['c'] = 1

    def _floatraiseskey(self):
        self.t[2.5] = 1

    def _noneraiseskey(self):
        self.t[None] = 1

    def _stringraisesvalue(self):
        self.t[1] = 'c'

    def _floatraisesvalue(self):
        self.t[1] = 1.4

    def _noneraisesvalue(self):
        self.t[1] = None

## Set tests

class TestIOSets(ExtendedSetTests, TestCase):
    def setUp(self):
        self.t = IOSet()

    def testNonIntegerInsertRaises(self):
        self.assertRaises(TypeError,self._insertstringraises)
        self.assertRaises(TypeError,self._insertfloatraises)
        self.assertRaises(TypeError,self._insertnoneraises)

    def _insertstringraises(self):
        self.t.insert('a')

    def _insertfloatraises(self):
        self.t.insert(1.4)

    def _insertnoneraises(self):
        self.t.insert(None)

class TestOOSets(ExtendedSetTests, TestCase):
    def setUp(self):
        self.t = OOSet()

class TestIISets(ExtendedSetTests, TestCase):
    def setUp(self):
        self.t = IISet()

class TestOISets(ExtendedSetTests, TestCase):
    def setUp(self):
        self.t = OISet()

class TestIOTreeSets(NormalSetTests, TestCase):
    def setUp(self):
        self.t = IOTreeSet()
        
class TestOOTreeSets(NormalSetTests, TestCase):
    def setUp(self):
        self.t = OOTreeSet()

class TestIITreeSets(NormalSetTests, TestCase):
    def setUp(self):
        self.t = IITreeSet()

class TestOITreeSets(NormalSetTests, TestCase):
    def setUp(self):
        self.t = OITreeSet()
        
## Bucket tests

class TestIOBuckets(BucketTests, TestCase):
    def setUp(self):
        self.t = IOBucket()

class TestOOBuckets(BucketTests, TestCase):
    def setUp(self):
        self.t = OOBucket()

class TestIIBuckets(BucketTests, TestCase):
    def setUp(self):
        self.t = IIBucket()

class TestOIBuckets(BucketTests, TestCase):
    def setUp(self):
        self.t = OIBucket()

def test_suite():
    TIOBTree = makeSuite(TestIOBTrees, 'test')
    TOOBTree = makeSuite(TestOOBTrees, 'test')
    TOIBTree = makeSuite(TestOIBTrees, 'test')
    TIIBTree = makeSuite(TestIIBTrees, 'test')

    TIOSet = makeSuite(TestIOSets, 'test')
    TOOSet = makeSuite(TestOOSets, 'test')
    TOISet = makeSuite(TestIOSets, 'test')
    TIISet = makeSuite(TestOOSets, 'test')

    TIOTreeSet = makeSuite(TestIOTreeSets, 'test')
    TOOTreeSet = makeSuite(TestOOTreeSets, 'test')
    TOITreeSet = makeSuite(TestIOTreeSets, 'test')
    TIITreeSet = makeSuite(TestOOTreeSets, 'test')

    TIOBucket = makeSuite(TestIOBuckets, 'test')
    TOOBucket = makeSuite(TestOOBuckets, 'test')
    TOIBucket = makeSuite(TestOIBuckets, 'test')
    TIIBucket = makeSuite(TestIIBuckets, 'test')
    
    alltests = TestSuite((TIOSet, TOOSet, TOISet, TIISet,
                          TIOTreeSet, TOOTreeSet, TOITreeSet, TIITreeSet,
                          TIOBucket, TOOBucket, TOIBucket, TIIBucket,
                          TOOBTree, TIOBTree, TOIBTree, TIIBTree))

    return alltests



## utility functions

def lsubtract(l1, l2):
   l1=list(l1)
   l2=list(l2)
   l = filter(lambda x, l1=l1: x not in l1, l2)
   l = l + filter(lambda x, l2=l2: x not in l2, l1)
   return l

def realseq(itemsob):
    return map(lambda x: x, itemsob)


def main():
    TextTestRunner().run(test_suite())

if __name__ == '__main__':
    main()