Mailman 3 October 2009 - Twisted

[Twisted-Python] Django + Twisted trunk, fresh virtualenv, simplest demo
by ssteinerX＠gmail.com 31 Oct '09

31 Oct '09

Hi! I was pulling my hair out yesterday, trying to get my Django application's forms working on both the development server, and running under Twisted trunk. POST variables were not arriving in the REQUEST object where they belonged, but only under Twisted. So, I did the only logical thing; I made a completely isolated test case, now available at: https://github.com/ssteiner/twisted-django/ Along the way, I finally decided to start over from scratch with a brand new --no-site-packages virtualenv, then installed only what was absolutely required. The repository shows what I think may be the simplest way to run Django under Twisted WSGI which I pretty much stole wholesale from the Pinax WSGI setup. I'll be writing a blog post with a blow-by-blow shortly which I'll post when it's done but, for now, this is a very clear, and dead simple way to run Django under Twisted WSGI. Please note: you *must* be running a Twisted trunk checkout because some WSGI bugs have been fixed since the most recent release. S

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Re: [Twisted-Python] Using a custom reactor in twisted trial for test cases?
by Andrew Francis 30 Oct '09

30 Oct '09

Hi Crispin: Message: 8 Date: Fri, 30 Oct 2009 17:38:12 +0800 From: Crispin Wellington <cwellington(a)ccg.murdoch.edu.au> Subject: [Twisted-Python] Using a custom reactor in twisted trial for test cases? To: twisted-python(a)twistedmatrix.com Message-ID: <1256895492.4200.9.camel@wolfwood> Content-Type: text/plain >I am using twisted trial to run test cases for an application. The >application however uses stackless python and has a custom stackless >reactor. I implemented this reactor like this... For better or worse, much of what you have discussed have been fleshed out about two years ago in this mailing list and in stackless. Also I outline strategies in the PyCon 2008 talk "Adventures in Stackless Twisted Integration." Personally, I don't know why more people don't use Stackless with Twisted. Some advice: 1) Based on what I have seen, you don't need to write a custom reactor (I still remember Glyph setting me straight on that one). At least for what you are doing :-). 2) Use task.loopingCall to make the reactor periodically yield. l = task.LoopingCall(stackless.schedule) l.start(.01) however there is some weird interaction between Stackless Python 2.6 and Twisted so you may have to do task.LoopingCall(__tick__) def __tick__(): stackless.schedule or play with the recursionlimit variable. I have not gotten to the bottom of that problem. Cheers, Andrew

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[Twisted-Python] Regarding Ticket 3629, Error in adbapi Connection Pool in cleanup
by Vishal Shetye 30 Oct '09

30 Oct '09

Hi, I was facing the issue as noted here http://twistedmatrix.com/trac/ticket/3629. As I see, python 2.5 can be build with pysqlite2.1.3 and sqlite 3.0.8 or later. However, support for a connection to be moved across multiple threads was added to sqlite at version3.3.1. Last comment in the ticket says, the module is just overprotective. Which module is he referring to and why is it said that it is overprotective? Is he referring to the pysqlite module? He says using check_same_thread=False is safe, is he saying it specifically in the twisted's context? Is it really safe even if I am using sqlite version between 3.0.8 to 3.3.1? -- vishal

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Re: [Twisted-Python] sleeping in inlineCallbacks
by Terry Jones 29 Oct '09

29 Oct '09

>>>>> "Brian" == Brian Granger <ellisonbg.net(a)gmail.com> writes: Brian> I looked at deferLater, but am not using it right now. The sleep Brian> function I am using is basically the same as this - in my case Brian> "sleep" turned out to be a little simpler because I don't have to Brian> create and pass the clock around. But I will probably use Brian> deferLater for this same purpose in the future as well. Hi Brian Forgive me for butting in, but.... why :-) Importing the reactor is no big deal, and if you use task.deferLater, apart from not having to write any code you also have the advantage of being able to pass it a result that the deferred will be called with. For this reason you can also put a task.deferLater result into a callback chain to achieve an async sleep and it will duly pass the result along. E.g.: from twisted.internet import reactor, task, defer d = somethingReturningADeferred() d.addCallback(lambda x: task.deferLater(reactor, 5.0, defer.passthru, x)) Terry

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[Twisted-Python] Working on multiple Twisted branches
by ssteinerX＠gmail.com 29 Oct '09

29 Oct '09

So... I am very interested in the improvements to the Twisted Web Client portion of Twisted and have been wanting to review two tickets/ branches in particular; 3987 and 886. Today I finally got around to getting the branches checked out and merged, with some great help from `ivan` on IRC and, wrote a blog post detailing exactly how to do it. http://websaucesoftware.com/blog/?p=434 It uses Git instead of Subversion for the actual merges so it didn't suck anywhere as much as it would have with Subversion alone. Comments/corrections always welcome. S

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Re: [Twisted-Python] Can browse, but getPage() fails on localhost address
by Terry Jones 29 Oct '09

29 Oct '09

>>>>> "Steve" == Steve Steiner (listsin) <listsin(a)integrateddevcorp.com> writes: Steve> curl http://localhost/w3c-validator/check <-- returns HTML code Steve> any browser to http://localhost/w3c-validator/check <-- returns HTML code Steve> t.w.c.getPage("http://localhost/w3c-validator/check") <-- 404 Steve> wget http://localhost/w3c-validator/check <-- 404 Steve> So what the heck is the difference in how these things resolve that Steve> address!? When you say 404, do you really mean that you get a 404? Or are you just saying that to informally tell us that it doesn't work? If the former, then it seems this has nothing to do with DNS and host names. The connection is being made in all cases. It looks like there's something different about the HTTP requests that causes the server to react differently. You're writing the server, correct? Can you log output? If the latter, then I guess you really mean that the connection fails. Terry

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[Twisted-Python] Can browse, but getPage() fails on localhost address
by Steve Steiner (listsin) 29 Oct '09

29 Oct '09

I can browse to either URL in any browser, getPage() works fine on the external address, 404's on the localhost address. Any insight greatly appreciated; this is about as simple a test case as there can be and I'm mystified as to why it's not working. Of course, that probably means I'll feel like a complete moron when someone clops me on the head with the answer, but I can deal with that... Thanks, S Just in case it gets mutilated by mail: http://pastebin.com/d2f80ce0a from twisted.web import client def showPage(pageData): print pageData reactor.stop() def handleError(failure): print "Error:", failure.getErrorMessage() failure.printDetailedTraceback() reactor.stop() if __name__ == "__main__": from twisted.internet import reactor # postRequest = client.getPage("http://localhost/w3c-validator/check ") postRequest = client.getPage("http://validator.w3.org/check") postRequest.addCallback(showPage).addErrback(handleError) reactor.run()

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[Twisted-Python] sleeping in inlineCallbacks
by Paul Thomas 29 Oct '09

29 Oct '09

Is there any way to do something like "yield sleep(10)" inside an @inlineCallbacks method?

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[Twisted-Python] Regarding Twisted Matrix
by naman jain 28 Oct '09

28 Oct '09

Hi, I have a client server model in twisted, where the server spawns a thread ( basically a test script in python that runs for about 20 mins) I want to track the progress of the thread, and send the progress to the client back So, I write something like this in my server: parent_conn, child_conn = Pipe() thread = Process(target = start_test.main_func, args=(SCRIPT_PATH, TEMP_OUTPUT_PATH, self.output_name, child_conn)) thread.start() response = parent_conn.recv() print response //prints like: initialization done self.transport.write(response) response = parent_conn.recv() print response // configuration done self.transport.write(response) . . . thread.join() But the transport.write calls don't send at the same time. instead they wait for the thread to finish (coz of thread.join) and then append all the response and send it back; like "initialization doneconfiguration done...done" thereby defeating the purpose of creating a thread. How do I give the control to the reactor to write the data back, and still keep the thread running? or is there any other way these kinda of progress can be tracked ? I am kinda stuck with this :(

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Re: [Twisted-Python] Hotdot
by Alex Clemesha 27 Oct '09

27 Oct '09

Run the example *not* as root, then it will work. sys.path is different for the root user, that is the problem. -Alex On Tue, Oct 27, 2009 at 11:17 AM, Alfredo Veltri <alfredo.veltri(a)digitalia.it> wrote: > Hi Alex, > i'm trying with hotdot. > i receive the following errors. Would help me about that? > Thanks in advance. > > root@myhome:/var/www/clemesha-hotdot-522849b/djangoweb# cd > . > > root@myhome:/var/www/clemesha-hotdot-522849b# ls > > djangoweb README.rst realtime server.py static > > root@myhome:/var/www/clemesha-hotdot-522849b# twistd -ny > server.py > > Traceback (most recent call last): > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/application/app.py" > , line 690, in run > runApp(config) > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/scripts/twistd.py" > , line 23, in runApp > _SomeApplicationRunner(config).run() > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/application/app.py" > , line 411, in run > self.application = self.createOrGetApplication() > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/application/app.py" > , line 494, in createOrGetApplication > application = getApplication(self.config, passphrase) > --- <exception caught here> --- > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/application/app.py" > , line 505, in getApplication > application = service.loadApplication(filename, style, > passphrase) > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/application/service.py" > , line 390, in loadApplication > application = sob.loadValueFromFile(filename, > 'application', passphrase) > File > "/usr/local/lib/python2.6/dist-packages/Twisted-8.2.0_r27386-py2.6-linux-i686.egg/twisted/persisted/sob.py" > , line 210, in loadValueFromFile > exec fileObj in d, d > File "server.py", line 25, in <module> > from djangoweb.twisted_wsgi import get_root_resource > exceptions.ImportError: No module named > djangoweb.twisted_wsgi > > Failed to load application: No module named > djangoweb.twisted_wsgi > > -- Alex Clemesha clemesha.org

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