The whole point of creating and populating an OptionParser is to call
its \method{parse{\_}args()} method:
\begin{verbatim}
-(options, args) = parser.parse_args(args=None, options=None)
+(options, args) = parser.parse_args(args=None, values=None)
\end{verbatim}
where the input parameters are
\begin{description}
\item[\code{args}]
the list of arguments to process (default: \code{sys.argv{[}1:]})
-\item[\code{options}]
+\item[\code{values}]
object to store option arguments in (default: a new instance of
optparse.Values)
\end{description}