Events: The Python Way

[kyosohma at gmail.com]

On Jul 29, 3:14 pm, "Gianmaria" <gianma... at hotmail.com> wrote:
> "David Wilson" <d... at botanicus.net> ha scritto nel messaggionews:mailman.1295.1185665717.22759.python-list at python.org...
>
>
>
> > Hi there,
>
> > Python has no built-in way of doing this. You may consider writing
> > your own class if you like this pattern (I personally do):
>
> > class Event(object):
> >    def __init__(self):
> >        self.subscribers = set()
>
> >    def __iadd__(self, subscriber):
> >        self.subscribers.add(subscriber)
> >        return self
>
> >    def __isub__(self, subscriber):
> >        self.subscribers.pop(subscriber)
> >        return self
>
> >    def __call__(self, *args, **kwargs):
> >        for subscriber in self.subscribers:
> >            subscriber(*args, **kwargs)
>
> > def HandleFoo(strng):
> >    print "HandleFoo:", strng
>
> > OnFoo = Event()
> > OnFoo += HandleFoo
>
> > OnFoo("Test.")
>
> > On 29/07/07, Gianmaria <gianma... at hotmail.com> wrote:
> >> Hi,
> >> i'm a .net programmer and i'm learnig python, so this question can be
> >> very
> >> stupid or easy for python programmers. I've a doubt about events.... here
> >> is
> >> what:
>
> >> in c# for example i can write a delegate and an event in this way...
>
> >> public delegate SomethingChangedHandler(string message);
> >> public event SomethingChangedHandler SomethingChanged;
>
> >> and later in the code fire this event in this way...
>
> >> if(SomethingChanged != null)
> >> {
> >>     SomethingChanged("Nothing important");
> >> }
>
> >> and the subscription of this event of other objects can be easy as
>
> >> eventGeneratorObject.SomethingChanged += new
> >> SomethingChangedHandler(aFunctionto_takecareof_it);
>
> >> and even the handlig of the event is aesy...
>
> >> void aFunctionto_takecareof_it(string msg)
> >> {
>
> >> }
>
> >> ....now the question is.. how can i do the same using Python? Every help
> >> is
> >> appreciated
>
> >> Regards,
> >> Gianmaria
>
> >> --
> >>http://mail.python.org/mailman/listinfo/python-list
>
> Txs so much.
> Gianmaria

I think the pubsub module in wxPython does what you are referring to.
Of course, usually you would need to be writing a GUI if you used it.
Here's some links on it:

http://www.wxpython.org/docs/api/wx.lib.pubsub-module.html
http://www.wxpython.org/docs/api/wx.lib.pubsub.PublisherClass-class.html

They also mention it in their wiki / cookbook. Unfortunately, the
wxPython website seems screwed up today. I've never seen it behave
like this. But when it's back up, I'd highly recommend checking it
out. Or just browse Google's cached copies...

Mike