List files for a package file

def _local_list_files(self, args):
        '''
        List files for a package file
        '''
        if len(args) < 2:
            raise SPMInvocationError('A package filename must be specified')

        pkg_file = args[1]
        if not os.path.exists(pkg_file):
            raise SPMPackageError('Package file {0} not found'.format(pkg_file))
        formula_tar = tarfile.open(pkg_file, 'r:bz2')
        pkg_files = formula_tar.getmembers()

        for member in pkg_files:
            self.ui.status(member.name)