[Zope-CVS] CVS: Products/ZCTextIndex/tests - testNBest.py:1.1.2.1

[Tim Peters]

Update of /cvs-repository/Products/ZCTextIndex/tests
In directory cvs.zope.org:/tmp/cvs-serv6649/tests

Added Files:
      Tag: TextIndexDS9-branch
	testNBest.py 
Log Message:
Adding an NBest object to remember the N best-scoring objects passed to
it.  This is intended to be used for final result lists.  The dirt-simple
sorted-list + bisect.bisect implementation has the right theoretical
worst-case number of comparisons, but for large N a min-heap would
eventually win on data-movement cost.  But don't optimize this
prematurely!  I suspect it will work fine as-is.


=== Added File Products/ZCTextIndex/tests/testNBest.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.
#
##############################################################################

from unittest import TestCase, TestSuite, main, makeSuite

from Products.ZCTextIndex.NBest import NBest

class NBestTest(TestCase):

    def testConstructor(self):
        self.assertRaises(ValueError, NBest, 0)
        self.assertRaises(ValueError, NBest, -1)

        for n in range(1, 11):
            nb = NBest(n)
            self.assertEqual(len(nb), 0)
            self.assertEqual(nb.capacity(), n)

    def testOne(self):
        nb = NBest(1)
        nb.add('a', 0)
        self.assertEqual(nb.getbest(), [('a', 0)])

        nb.add('b', 1)
        self.assertEqual(len(nb), 1)
        self.assertEqual(nb.capacity(), 1)
        self.assertEqual(nb.getbest(), [('b', 1)])

        nb.add('c', -1)
        self.assertEqual(len(nb), 1)
        self.assertEqual(nb.capacity(), 1)
        self.assertEqual(nb.getbest(), [('b', 1)])

    def testMany(self):
        import random
        n = 10
        inputs = []
        for i in range(50):
            inputs.append((i, i))
        expected = inputs[-n:]
        expected.reverse()

        # Feed them in in increasing order.
        nb = NBest(n)
        for item, score in inputs:
            nb.add(item, score)
        self.assertEqual(len(nb), n)
        self.assertEqual(nb.capacity(), n)
        self.assertEqual(nb.getbest(), expected)

        # Feed them in in decreading order.
        nb = NBest(n)
        inputs.reverse()
        for item, score in inputs:
            nb.add(item, score)
        self.assertEqual(len(nb), n)
        self.assertEqual(nb.capacity(), n)
        self.assertEqual(nb.getbest(), expected)

        # Feed them in in random order.

        nb = NBest(n)
        random.shuffle(inputs)
        for item, score in inputs:
            nb.add(item, score)
        self.assertEqual(len(nb), n)
        self.assertEqual(nb.capacity(), n)
        self.assertEqual(nb.getbest(), expected)

def test_suite():
    return makeSuite(NBestTest)

if __name__=='__main__':
    main(defaultTest='test_suite')