# Taken from Lib/test/test_builtin.py of Python 2.3.4

import test.test_support, unittest

class Squares:

    def __init__(self, max):
        self.max = max
        self.sofar = []

    def __len__(self): return len(self.sofar)

    def __getitem__(self, i):
        if not 0 <= i < self.max: raise IndexError
        n = len(self.sofar)
        while n <= i:
            self.sofar.append(n*n)
            n += 1
        return self.sofar[i]

class SumBuiltinTest(unittest.TestCase):    
    def test_sum(self):
        self.assertEqual(sum([]), 0)
        self.assertEqual(sum(range(2,8)), 27)
        self.assertEqual(sum(iter(range(2,8))), 27)
        self.assertEqual(sum(Squares(10)), 285)
        self.assertEqual(sum(iter(Squares(10))), 285)
        self.assertEqual(sum([[1], [2], [3]], []), [1, 2, 3])

        self.assertRaises(TypeError, sum)
        self.assertRaises(TypeError, sum, 42)
        self.assertRaises(TypeError, sum, ['a', 'b', 'c'])
        self.assertRaises(TypeError, sum, ['a', 'b', 'c'], '')
        self.assertRaises(TypeError, sum, [[1], [2], [3]])
        self.assertRaises(TypeError, sum, [{2:3}])
        self.assertRaises(TypeError, sum, [{2:3}]*2, {2:3})
        
def test_main():
    test.test_support.run_unittest(SumBuiltinTest)

if __name__ == "__main__":
    test_main()