def packages(pkg_list, update=False):
 pkg_list = [pkg for pkg in pkg_list if (not is_installed(pkg))]
 if pkg_list:
  install(pkg_list, update)

def packages ( pkg_list , update = False ) : pkg_list = [ pkg for pkg in pkg_list if ( not is_installed ( pkg ) ) ] if pkg_list : install ( pkg_list , update )
require several smartos packages to be installed .