Python dbus ne peut pas trouver org. (Gnome | freedesktop) .ScreenSaver

Question

J'essaye d'obtenir l'interaction de python avec dbus et l'économiseur d'écran mais il refuse catégoriquement de le faire n'importe quoi. Perl semble faire bien avec elle, mais j'écris python, perl pas (encore)

Python 2.6.6 (r266:84292, Sep 15 2010, 16:22:56) 
[GCC 4.4.5] on linux2 
Type "help", "copyright", "credits" or "license" for more information. 
>>> import dbus 
>>> bus = dbus.SystemBus() 
>>> ofn = 'org.freedesktop.ScreenSaver' 
>>> bus.get_object(ofn, "/org/freedesktop/ScreenSaver") 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
    File "/usr/lib/pymodules/python2.6/dbus/bus.py", line 244, in get_object 
    follow_name_owner_changes=follow_name_owner_changes) 
    File "/usr/lib/pymodules/python2.6/dbus/proxies.py", line 241, in __init__ 
    self._named_service = conn.activate_name_owner(bus_name) 
    File "/usr/lib/pymodules/python2.6/dbus/bus.py", line 183, in activate_name_owner 
    self.start_service_by_name(bus_name) 
    File "/usr/lib/pymodules/python2.6/dbus/bus.py", line 281, in start_service_by_name 
    'su', (bus_name, flags))) 
    File "/usr/lib/pymodules/python2.6/dbus/connection.py", line 620, in call_blocking 
    message, timeout) 
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.ScreenSaver was not provided by any .service files 
>>> 

Voici ce que j'ai vu dans d'autres endroits en Perl:

my $cmd = "dbus-monitor --session \"type='signal',interface='org.gnome.ScreenSaver',member='SessionIdleChanged'\""; 

open (IN, "$cmd |"); 

while (<IN>) { 
if (m/^\s+boolean true/) { 
    #print something 
} elsif (m/^\s+boolean false/) { 
    #print something else 
} 
} 

Answer 1

In [36]: import dbus 

In [37]: bus = dbus.SessionBus() 

In [38]: bus.get_object('org.gnome.ScreenSaver','/org/gnome/ScreenSaver') 
Out[38]: <ProxyObject wrapping <dbus._dbus.SessionBus (session) at 0xa41e38c> :1.24 /org/gnome/ScreenSaver at 0xa4a3b0c>