Mailman 3 November 2008 - Twisted

Re: [Twisted-Python] A Python metaclass for Twisted allowing __init__ to return a Deferred
by Terry Jones Nov. 4, 2008

Nov. 4, 2008

Hi Glyph Thanks for the further examples. I agree that the classmethod approach is both flexible and powerful. It's probably the most useful thing I've picked up out of thinking about and playing with all this. Terry

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[Twisted-Python] October Sponsored Development
by Jean-Paul Calderone Nov. 3, 2008

Nov. 3, 2008

Hey all, Just wanted to let everyone know that the summary of the latest round of sponsored Twisted development is up on the labs blog: http://labs.twistedmatrix.com/2008/11/summary-of-october-sponsored-twisted.… Jean-Paul

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[Twisted-Python] RPython and Twisted
by Andrew Francis Nov. 3, 2008

Nov. 3, 2008

Hi Folks: This is new to me so here goes..... I am taking my first baby steps with PyPy. I wish to start experimenting by re-writing an example (the programme I posted in RPtyhon and converting it to C. However I want to still use Twisted for networking. One approach I was thinking about was to somehow compile the program as a C extension library and somehow have it talk to Twisted - I would like to keep my code and Twisted in the same process. Am I on the right track? Any hints would be … [View More]

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[Twisted-Python] Persistent Queue with subscriber worker
by Daniel de la Cuesta Nov. 3, 2008

Nov. 3, 2008

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Re: [Twisted-Python] A Python metaclass for Twisted allowing __init__ to return a Deferred
by Terry Jones Nov. 3, 2008

Nov. 3, 2008

>>>>> "Esteve" == Esteve Fernandez <esteve(a)sindominio.net> writes: Esteve> Alternatively a function would suffice: [snip] Esteve> def FooFactory(value): Esteve> return aFuncReturningADeferred(value).addCallback(SimpleFoo) Right. That's JP's solution (though he didn't bother wrapping it in a func): pass the result of the Deferred to the constructor of the class. But I like your __new__ approach better, as it puts the logic for creating deferreds, adding … [View More]

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Re: [Twisted-Python] A Python metaclass for Twisted allowing __init__ to return a Deferred
by Terry Jones Nov. 3, 2008

Nov. 3, 2008

>>>>> "Esteve" == Esteve Fernandez <esteve(a)sindominio.net> writes: Esteve> I'm going to jump in. How about this: That's nice. But you've coupled the args to aFuncReturningADeferred and what it's Deferred ends up returning to the args for __init__ of the class. I think you meant this: from twisted.internet import defer, reactor def aFuncReturningADeferred(value): d = defer.Deferred() reactor.callLater(5, d.callback, value[::-1]) return … [View More]

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[Twisted-Python] A Python metaclass for Twisted allowing __init__ to return a Deferred
by Terry Jones Nov. 3, 2008

Nov. 3, 2008

I just posted a blog article with title as above: http://bit.ly/1whZUK Very briefly, I wrote a metaclass to allow you to write classes whose __init__ method uses deferreds. Your __init__ can create deferreds, call functions that return deferreds, and of course return a deferred itself (that's the whole point). Your class instance wont be available until after the deferred your __init__ returns has fired. You use it like this: from txDeferredInitMeta import TxDeferredInitMeta class … [View More]

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Re: [Twisted-Python] Passing arguments while running a twistd application
by Terry Jones Nov. 3, 2008

Nov. 3, 2008

>>>>> "Adriano" == Adriano Marques <py.adriano(a)gmail.com> writes: Adriano> I have a twisted application, which formely was run with command Adriano> line arguments which were used during runtime, eg: I was passing Adriano> the path to the log file as argument. Then, I decided to make my Adriano> app run through twistd as a tac file but then I'm not able to pass Adriano> command line arguments anymore. Is there any way to overcome this Adriano> issue? I … [View More]

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Re: [Twisted-Python] A Python metaclass for Twisted allowing __init__ to return a Deferred
by Terry Jones Nov. 3, 2008

Nov. 3, 2008

Hi Tristan >>>>> "Tristan" == Tristan Seligmann <mithrandi(a)mithrandi.net> writes: Tristan> You can, however, encapsulate it into a classmethod or free Tristan> function that you call to get an instance of MyClass. This is a Tristan> pattern often seen when there are various ways to build an Tristan> instance of some class; you'll have a very basic __init__, and Tristan> then a bunch of factory functions or classmethods that do more Tristan> complicated … [View More]

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Re: [Twisted-Python] A Python metaclass for Twisted allowing __init__ to return a Deferred
by Terry Jones Nov. 3, 2008

Nov. 3, 2008

Hi JP > I usually solve this kind of problem like this: > > d = aFuncReturningADeferred() > d.addCallback(MyClass) > d.addCallback(cb) See? I knew there'd be a 3-line solution somewhere :-) That's very cute, I'd never have thought of that... Python is so nice. My (weak?) response is that your solution isn't quite so general. What if I want __init__ to generate the deferred based on its args, or on the result of other functions called based on its args? Yes, I … [View More]

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