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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse_args(self, argv=None):
 """ Return an argparse.Namespace of the argv string or sys.argv if argv is None. """

        arg_input = shlex.split(argv) if argv is not None else None
        self.get_or_create_session()
        return self.argparser.parse_args(arg_input)