import unittest

from test import test_support

class Empty:

    def __repr__(self):

        return '<Empty>'

class Coerce:

    def __init__(self, arg):

        self.arg = arg

    def __repr__(self):

        return '<Coerce %s>' % self.arg

    def __coerce__(self, other):

        if isinstance(other, Coerce):

            return self.arg, other.arg

        else:

            return self.arg, other

class Cmp:

    def __init__(self,arg):

        self.arg = arg

    def __repr__(self):

        return '<Cmp %s>' % self.arg

    def __cmp__(self, other):

        return cmp(self.arg, other)

class ComparisonTest(unittest.TestCase):

    set1 = [2, 2.0, 2L, 2+0j, Coerce(2), Cmp(2.0)]

    set2 = [[1], (3,), None, Empty()]

    candidates = set1 + set2

    def test_comparisons(self):

        for a in self.candidates:

            for b in self.candidates:

                if ((a in self.set1) and (b in self.set1)) or a is b:

                    self.assertEqual(a, b)

                else:

                    self.assertNotEqual(a, b)

    def test_id_comparisons(self):

        # Ensure default comparison compares id() of args

        L = []

        for i in range(10):

            L.insert(len(L)//2, Empty())

        for a in L:

            for b in L:

                self.assertEqual(cmp(a, b), cmp(id(a), id(b)),

                                 'a=%r, b=%r' % (a, b))

def test_main():

    test_support.run_unittest(ComparisonTest)

if __name__ == '__main__':

    test_main()