python - How to UT OptionParser()? -

how can unittest code snippet?

def parse_arguments():     parser = optionparser()     parser.add_option("--debug",                   action="store_true",                   default=false)     parser.add_option("--auto",                   action="store_true",                   default=false)      (params, args) = parser.parse_args()      return params 

i tried example:

class testparsearguments(unittest.testcase):     def setup(self):         self.parser = parse_arguments()         sys.argv.append(['--auto'])      def test_something(self):         parsed = self.parser.parse()         self.asserttrue(parsed.auto)         self.assertfalse(parsed.debug) 

i tried find example google did not find anything. looking advice, thanks.