import unittest

class TestExceptionStringRoundTrip(unittest.TestCase):
    def assertStrCast(self, ExceptionClass):
        s = "hello"
        self.assertEqual(s, str(ExceptionClass(s)))

for builtin in dir(__builtins__):
    if builtin.endswith('Error') or builtin.endswith('Exception'):
        def _test(self, ExceptionClass=builtin):
            self.assertStrCast(getattr(__builtins__, ExceptionClass))
        setattr(TestExceptionStringRoundTrip, "test%s" % builtin,
                _test)

if __name__ == "__main__":
    unittest.main()