title: Having options in argparse with a dash
body: <p>I want to have some options in argparse module such as <code>--pm-export</code> however when I try to use it like <code>args.pm-export</code> I get the error that there is not attribute <code>pm</code>. How can I get around this issue? Is it possible to have <code>-</code> in command line options?</p>