Mailman 3 April 2008 - Twisted

[Twisted-Python] Problems with trial in 8.0.1
by Brian Granger April 10, 2008

April 10, 2008

Hi, I just got around to installing twisted 8.0.1 (from the tarball) and I see the following when I run trial twisted Traceback (most recent call last): File "/usr/local/bin/trial", line 5, in <module> pkg_resources.run_script('Twisted==8.0.1', 'trial') File "/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/pkg_resources.py", line 448, in run_script File "/System/Library/Frameworks/Python.framework/Versions/2.5/Extras/lib/python/pkg_resources.py", … [View More]

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[Twisted-Python] failures, errbacks and exception handling
by Atilla April 9, 2008

April 9, 2008

Im a little confused when it comes to handling some errors in twisted. More specifically - when it comes to processing failures that are raised in adbapi. Now - when runInteraction succeeds, all is ok and things are commited, that's nice and clean. When it raises an error, I can do two things - either wrap my calls inside the callable passes to runInteraction in Try:Except, or attach an errback. I'm not exactly sure which one to take. I only need to catch specific exceptions - Mysql … [View More]

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[Twisted-Python] Re: [Stackless] Deferreds and Tasklets
by Simon Pickles April 9, 2008

April 9, 2008

Carlos Eduardo de Paula wrote: > Hi Simon, > > Have you looked at the examples project? I made a small example using > PB in a producer/consumer demo where the producers and consumers > access a shared pool in a server using PB. > > You can see it here: > > http://code.google.com/p/stacklessexamples/wiki/StacklessTwisted Oh yeah! This is really great. I'd seen this a while back, but forget it was combining stackless/twisted so nicely! Thanks! > > http://… [View More]stacklessexamples.googlecode.com/svn/trunk/examples/twisted/twistedP… > > http://stacklessexamples.googlecode.com/svn/trunk/examples/twisted/twistedP… > > > Regards, > > Carlos > > > On 06/04/2008, at 13:42, Simon Pickles wrote: > >> So I am still fiddling with interesting ways to combine stackless and >> twisted. Its fun, but I am probably naively hacking! (I always seem to >> want to use the deprecated code!- probably says a lot about me?) >> >> I'm using Perspective Broker to do remote calls to an app running >> Twisted-Stackless. PB is positively brilliant, btw. >> >> So say the a remote caller wants to get data from my app. It calls >> remote_GetData() in my PB app, which uses the actor model(each object >> has a channel.receive() running in its own tasklet). >> >> remote_GetData() has to send a message thru a stackless.channel() to get >> the required data, then it must stackless.schedule() >> >> Now it waits for the result to arrive at its own channel.receive(), >> which then needs to be passed back as the return value of >> remote_GetData(). >> >> Is this possible? >> >> Perhaps like this: >> >> from twisted.spread import pb >> from twisted.internet import reactor >> import stackless >> >> dbRx = stackless.channel() >> pbRx = stackless.channel() >> >> class DataSource: >> def Listen(self): >> while 1: >> msg = dbrx.receive() # a channel will arrive here >> msg.send(42) >> stackless.schedule() >> def __init__(self): >> stackless.tasklet(self.Listen)() >> >> >> class pbBroker(pb.Referenceable): >> def remote_GetData(self): >> dbRx.send(pbRx) >> result = pbRx.receive() >> # return 42 to remote caller thru pb >> return result >> >> This isn't ideal since I don't want pbBroker to block during the >> receive. I'd like it to closer resemble the Listen loop of the first >> class, so other objects can talk to pbBroker while it is waiting. Maybe >> like this: >> >> class pbBroker(pb.Referenceable): >> def Listen(self): >> while 1: >> msg = self.rx.receive() >> # do stuff with msg from other local objects >> stackless.schedule() >> def __init__(self): >> self.rx = stackless.channel() >> stackless.tasklet(self.Listen)() >> def remote_GetData(self): >> ch = stackless.channel() >> dbRx.send(ch) >> # can block since its a dedicated channel >> result = ch.receive() >> # return 42 to remote caller thru pb >> return result >> I guess the same problem arise when remote_GetData() has to use a >> deferred too. >> >> from twisted.enterprise import adbapi >> dbPool = adbapi.ConnectionPool("MySQLdb", db="db", user="user", >> passwd="pw") >> >> class pbBroker(pb.Referenceable): >> def remote_GetDeferredData(self): >> d = dbPool.runInteraction(DoQuery, "SELECT * FROM users") # >> DoQuery just wraps a query with try/except >> d.addCallback(self.GetDeferredData_Success) >> >> def GetDeferredData_Success(self, result): >> # return to remote caller thru pb >> return result ## WRONG >> >> How can I return a value for a remote_* call when I only get that value >> thru another callback? >> >> Sorry its a long and confusing one! >> >> Simon >> >> >> -- >> Linux user #458601 - http://counter.li.org. >> >> >> >> >> >> -- >> Linux user #458601 - http://counter.li.org. >> >> >> >> >> _______________________________________________ >> Stackless mailing list >> Stackless(a)stackless.com >> http://www.stackless.com/mailman/listinfo/stackless > > > -- Linux Counter: User# 424693 [View Less]

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[Twisted-Python] April 20 Sprint
by glyph＠divmod.com April 9, 2008

April 9, 2008

We're planning on having a sprint at the Divmod and Synthesis Studios offices in Cambridge, MA on April 20. While I know that some people who might be there will probably be working on twisted.conch, twisted.words, and twisted.web, the main purpose of these sprints is to help facilitate the expansion of the Twisted community. This sprint will have a little more planning than the last 3, which is to say "some, but not much". I'd like to get a feel for how many people would like to come, … [View More]

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[Twisted-Python] Problem with unittesting HTTP POST resource
by Teemu Harju April 9, 2008

April 9, 2008

Hi, I'm kind of a newbie in what comes to using Twisted and I'm stuck with a problem that I cannot seem to solve. My problem is that I'm experimenting with "trial" to be able to test my code. (I've heard that it is a wise thing to do ;-)). What I have is a simple HTTP resource that allows POSTing data. I made this example to illustrate my problem... import urllib from twisted.internet import reactor from twisted.web import resource, server, client, error from twisted.trial import unittest … [View More]

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Proposed tracker tag (was Re: [Twisted-web] Re: [Twisted-Python] Thumbs up for TwistedWebPlan)
by Jonathan Lange April 9, 2008

April 9, 2008

On Wed, Apr 9, 2008 at 10:03 AM, Phil Christensen <phil(a)bubblehouse.org> wrote: > I'd really love it if someone could help me with my web1 port of web2's > WSGI module. It's completely functional, and no longer has any dependencies > on web2, but it needs unit tests. > > http://twistedmatrix.com/trac/ticket/2753 > > I started working on imitating the test for the web2 version > (twisted/web2/test/test_wsgi.py), but it's been idling in my workspace for &… [View More]

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Re: [Twisted-Python] April 20 Sprint
by Andrew Francis April 7, 2008

April 7, 2008

Hi Glyph and Colleagues: >We're planning on having a sprint at the Divmod and >Synthesis Studios offices in Cambridge, MA on April >20. Boston is close and I have never been there. Not sure how busy I am that week. Also I am not sure what a sprint entails. Off the bat, stuff that would interest me is writing protocols (I am interested in MySQL), corotwine/stackless, SOA and Twisted. Cheers, Andrew … [View More]

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Re: [Twisted-Python] Deferreds and Tasklets
by Andrew Francis April 7, 2008

April 7, 2008

Hi Simon: [quote] So I am still fiddling with interesting ways to combine stackless and twisted. Its fun, but I am probably naively hacking! (I always seem to want to use the deprecated code!- probably says a lot about me?) [/quote] Simon I am all for fiddling! I was lucky to be around some great fiddlers. "Adventures in Stackless Python / Twisted Integration" is about my fiddling. One of the things I tried to do with "Adventures" was show the how and why's of the basic techniques. If there … [View More]

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[Twisted-Python] Vertex or other P2P libraries for twisted?
by Vince Cate April 7, 2008

April 7, 2008

I would like a library that I can use from Twisted to help with peer-to-peer communication. I have looked at and tried Vertex: http://divmod.org/trac/wiki/UsingVertex This is the kind of thing I want. But I am having some problems with it. Are there other similar libraries out there? What are people using? The problem we have with Vertex is sending from Windows to Linux. We can do Linux to Windows. The error we get is in file ptcp.py in class PTCP def connect(self, factory, host, … [View More]

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[Twisted-Python] adbapi, transactions and threading
by Atilla April 7, 2008

April 7, 2008

I hope it won't be too confusing. I'm basically trying to make sure I've grasped the concept - do correct me on anything I am wrong about or my way of thinking confuses you, please. I'm not used to running blocking calls and deferToThread a lot, so I wanted to make sure I understand that correctly. Basically, the way I understand it - adbapi is just a deferToThread wrapper around the normal python API, correct? As in - if I used something different to access my database, for example - … [View More]

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