On May 20, 2009, at 6:10 PM, Tristan Seligmann wrote: > On Tue, May 12, 2009 at 1:39 PM, Terry Jones <te...@jon.es> wrote: >> If Python allowed me to return a deferred from __init__, my problem >> would >> vanish. That's not going to happen though, I know :-) > > Well, if you /really/ want to, you can implement that; something like: > > #### > from twisted.internet import defer > > class DeferredClass(object): > def __new__(cls, *a, **kw): > inst = super(DeferredClass, cls).__new__(cls, *a, **kw) > return defer.maybeDeferred(inst.__init__, *a, > **kw).addCallback(lambda ign: inst) > ####
That's a really succinct solution to the problem. I never even thought of using __new__ for this. I'm inclined to say this is a better solution than the decorator-based one I sent along a few days ago, just because it's so simple. OTOH, my approach has one additional feature that I think is pretty nice, which is that you can call instance methods on the init-deferred object before the __init__ callback has been triggered, even if they need some of that initialized state (thus returning a Deferred). -phil _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
