import unittest import win32com.client import win32com.test.util import win32com.server.util class Tester: _public_methods_ = [ 'TestValue' ] def TestValue(self, v): pass def test_ob(): return win32com.client.Dispatch(win32com.server.util.wrap(Tester())) class TestException(Exception): pass # The object we try and pass - pywin32 will call __float__ as a last resort. class BadConversions: def __float__(self): raise TestException() class TestCase(win32com.test.util.TestCase): def test_float(self): try: test_ob().TestValue(BadConversions()) raise Exception("Should not have worked") except Exception as e: assert isinstance(e, TestException) if __name__=='__main__': unittest.main()