List files for an installed package

def _list_files(self, args):
        '''
        List files for an installed package
        '''
        if len(args) < 2:
            raise SPMInvocationError('A package name must be specified')

        package = args[-1]

        files = self._pkgdb_fun('list_files', package, self.db_conn)
        if files is None:
            raise SPMPackageError('package {0} not installed'.format(package))
        else:
            for file_ in files:
                if self.opts['verbose']:
                    status_msg = ','.join(file_)
                else:
                    status_msg = file_[0]
                self.ui.status(status_msg)