Example for SystemDbus

#!/usr/bin/env python2
# -*- coding: utf-8 -*-

import gobject, commands, re
from dbus.service import BusName, Object, method
from dbus import SystemBus
from dbus.mainloop.glib import DBusGMainLoop

dbus_loop = DBusGMainLoop()
session = SystemBus(mainloop=dbus_loop)

class Ejemplo(Object):
    instancias = 0
    def __init__(self, bus, loop):
        # Nombre Conocido de la aplicación
        name = BusName('com.pacsyu.check', bus)
        self.loop = loop
        self.path = '/com/pacsyu/check'
        super(Ejemplo, self).__init__(name, self.path)

    @method(dbus_interface='com.pacsyu.check')
    def if_updates(self):
        sync = commands.getoutput('pacman -Sy')
        if re.findall('No address record', sync):
                raise NameError('NoConecction')
        try:
            updates = commands.getoutput('pacman -Qu')
            if updates:
                return True
            else:
                return False
        except NameError:
            return -1

    @method(dbus_interface='com.pacsyu.check')
    def salir(self):
        self.loop.quit()

loop = gobject.MainLoop()
gobject.threads_init()
ejemplo1 = Ejemplo(session, loop)
loop.run()