优化下面代码：def watcher_maintenance_config(target_status): """The Watcher supports set system maintenance mode. Stop audits execution while set system maintenance mode, resume audits execution while unset system maintenance mode. """ # Check the node is master host first then check exists # openstack-watcher-api service. is_master = is_master_host() is_active = is_watcher_api_active() if not (is_master and is_active): logger("Ignore %s system maintenance mode on the node which is not " "master or watcher api is not started on." % target_status) return False return execute(target_status)

下面是优化后的代码：

def watcher_maintenance_config(target_status):
    """The Watcher supports set system maintenance mode.

    Stop audits execution while set system maintenance mode, resume audits
    execution while unset system maintenance mode.
    """
    # Check the node is master host first then check exists
    # openstack-watcher-api service.
    if not (is_master_host() and is_watcher_api_active()):
        logger("Ignore %s system maintenance mode on the node which is not "
               "master or watcher api is not started on." % target_status)
        return False
    return execute(target_status)

在优化后的代码中，我将 `is_master_host()` 和 `is_watcher_api_active()` 的结果直接用于判断条件，避免了多次函数调用。这样可以提高代码的效率。