How to catch an OSError for invalid directory path or file in UnitTest in Python 3.x

TestCatchException.py

    def testValidatePathFile(self):

        with self.assertRaises(OSError) as cm:
            # self.handle.__ValidatePathFile()
            self.handle = exceptman.ExceptionListManager(path="/tm")

        err = cm.exception
        self.assertEqual(str(err), "[Errno 2] No such file or directory: '/tm'")