dbus-screensaver.py

#!/usr/bin/env python3

from gi.repository import GLib

import atexit
import dbus
import dbus.service
import dbus.mainloop.glib

class ScreenSaverProxy(dbus.service.Object):
    def __init__(self, conn, object_path):
        dbus.service.Object.__init__(self, conn, object_path)
        proxy = session_bus.get_object('org.mate.ScreenSaver','/org/mate/ScreenSaver')
        self.xiface = dbus.Interface(proxy, 'org.mate.ScreenSaver')
        self.active = []

    @dbus.service.method("org.freedesktop.ScreenSaver", in_signature='ss', out_signature='u')
    def Inhibit(self, a, b):
        c = self.xiface.Inhibit(a, b)
        self.active.append (c);
        print("Inhibit:", a, b, c)
        return c

    @dbus.service.method("org.freedesktop.ScreenSaver", in_signature='u', out_signature='')
    def UnInhibit(self, a):
        print("UnInhibit:", a)
        self.xiface.UnInhibit(a)
        self.active.remove (a);

    def cleanup (self):
        print("Cleanup..")
        for a in self.active:
            print("UnInhibit:", a)
            self.xiface.UnInhibit(a)


def unregister(proxy):
    proxy.cleanup()

if __name__ == '__main__':
    dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)

    session_bus = dbus.SessionBus()

    name = dbus.service.BusName("org.freedesktop.ScreenSaver", session_bus)
    proxy = ScreenSaverProxy(session_bus, '/org/freedesktop/ScreenSaver')

    atexit.register(unregister, proxy)

    mainloop = GLib.MainLoop()
    print("Running screensaver proxy.")
    mainloop.run()

Looks good 👍️