如何通过python和dbus创建systemd临时计时器和服务(systemd-run like)？

import dbus
from dbus import systemd1

bus = dbus.SystemBus()

manager_obj = bus.get_object('org.freedesktop.systemd1', '/org/freedesktop/systemd1')
manager = dbus.Interface(manager_obj, 'org.freedesktop.systemd1.Manager')

def create_timer(timer_name, time_delay):
    timer_path = manager.CreateTimer({'OnUnitActiveSec': time_delay})
    timer_obj = bus.get_object('org.freedesktop.systemd1', timer_path)
    timer = dbus.Interface(timer_obj, 'org.freedesktop.systemd1.Timer')
    timer_properties = dbus.Interface(timer_obj, 'org.freedesktop.DBus.Properties')
    timer_properties.Set('org.freedesktop.systemd1.Timer', 'Persistent', False)
    timer_properties.Set('org.freedesktop.systemd1.Timer', 'Unit', timer_name)
    return timer_path

def create_service(service_name, service_exec):
    service_path = manager.CreateService()
    service_obj = bus.get_object('org.freedesktop.systemd1', service_path)
    service = dbus.Interface(service_obj, 'org.freedesktop.systemd1.Service')
    service_properties = dbus.Interface(service_obj, 'org.freedesktop.DBus.Properties')
    service_properties.Set('org.freedesktop.systemd1.Service', 'ExecStart', service_exec)
    service_properties.Set('org.freedesktop.systemd1.Service', 'Unit', service_name)
    return service_path

# 创建一个5秒后执行的计时器和服务
timer_path = create_timer('example.timer', '5s')
service_path = create_service('example.service', '/bin/echo "Hello, World!"')

# 启动计时器和服务
manager.StartUnit(timer_path, 'replace')
manager.StartUnit(service_path, 'replace')