Mailman 3 December 2008 - Twisted

[Twisted-Python] Twisted Python 0.7.0 Prerelease Testing
by Glyph Lefkowitz Aug. 5, 2021

Aug. 5, 2021

hi there, folks: I'd really like to release 0.7.0 but I would like it to be at least a little bit tested before I do so. Could those of you with CVS trees check everything out and see if it performs as advertised? Deeper bugs than that will have to wait for the next release, but I'd at least like to know if it works for someone other than me. Thanks. ______ __ __ _____ _ _ | ____ | \_/ |_____] |_____| |… [View More]

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[Twisted-Python] regarding xml elements
by Raj kumar Oct. 2, 2013

Oct. 2, 2013

Hi, I have an xml file in my application, I have created an element using Example goes like this......... document.createElement("abc") and i appeneded it by using append() method. But how i can reflect this change to my xml file? and one more thing is i want to create element with some other parameters.... like............. <abc m=" " n=" "> </abc> and i have m and n values as strings with me. can anybody help me to create this element and write it to the existing xml … [View More]

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[Twisted-Python] Get IP of connecting client in XMLRPC server
by Remy C. Cool April 28, 2013

April 28, 2013

Hello, On 18 May 2004, the following message was posted to this mailinglist: Jp Calderone exarkun at divmod.com wrote: >Daniel Newton wrote: > > I have a simple XML-PRC server similar to the example below: > > from twisted.web import xmlrpc, server > > class Example(xmlrpc.XMLRPC): > """An example object to be published.""" > > def xmlrpc_add(self, a, b): > """Return sum of arguments.""" > return a + b def … [View More]

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[Twisted-Python] An XMPP client with SSL support
by Pedro Sanchez Sept. 18, 2009

Sept. 18, 2009

Hello, I have a sample XMPP client with the following structure: from twisted.words.protocols.jabber import client, jid from twisted.internet import reactor ... factory = client.basicClientFactory(myJid, myPasswd) reactor.connectTCP(host,5222,factory) reactor.run() It works well, I can connect to the XMPP server. But I would appreciate if some one could give me some hints on what's required to get the client to connect using a secure SSL link. Thanks, -- Pedro

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[Twisted-Python] SQLAlchemy and Twisted
by alex clemesha Feb. 13, 2009

Feb. 13, 2009

Hi, I didn't want to hijack the 'Twisted Presentation Materials..' thread, so I started this one ... First off, in the other thread, Glenn, you mentioned Storm. I have heard of Storm, but never got any deeper that noticing that it is still a work in progress (maybe things have settled down ?) If anyone has anything to say on how it might be a good choice with Twisted, please feel free to enlighten us! But, I hoping to solve some immediate problems with Twisted and SQLAlchemy, so ... >… [View More]

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[Twisted-Python] ssh v1 support
by Deniz Pecel Jan. 3, 2009

Jan. 3, 2009

Hi List Does twisted support ssh v1? thanks

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[Twisted-Python] spawning tasks after reactor?
by Darren Govoni Dec. 31, 2008

Dec. 31, 2008

Hi, I'm new to twisted and have a simple question. I want to run a threaded server that monitors a remote service and spawns queued/threaded tasks as it finds messages. I'm having trouble understanding how to do this after a reactor is running since the tasks are not set up before reactor.run(). I see reactor.callLater(). But I want to spawn the task immediately. I tried: reactor.callLater(0,self.some_method,object) but the method is not immediately invoked. It seems its not invoked at … [View More]

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[Twisted-Python] FTP LIST
by Simply for IT Dec. 30, 2008

Dec. 30, 2008

<http://twistedmatrix.com/pipermail/twisted-python/2008-December/018932.html> Hi Jean-Paul, thank you for your reply. I need to implement a new IFTPShell, right? I have tried to create a new class (with a list method), which is inherited from IFTPShell class itself, but I cannot get it accepted by the realm I posted before. Greg >IFTPShell is the way you control the behavior of the FTP server. To exclude >certain results from a directory listing, you would implement the `… [View More]

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[Twisted-Python] combining addCallback and callLater ?
by Arye Dec. 29, 2008

Dec. 29, 2008

Dear list, I would like to add a callback that delays the chain. In other words I would like to combine: defer.Deferred().addCallback and reactor.callLater The only solution I came up with was the code below. There must be a more elegant way to do this. Any ideas would be greatly appreciated, All the best, *************************begin from twisted.internet import reactor, defer def printResults(results, arg): print "In printResults results=", results print "In printResults arg=", … [View More]

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[Twisted-Python] Twisted and Urwid
by Christian Scharkus Dec. 28, 2008

Dec. 28, 2008

Hi folks. I've got a new question. After recongnising that the python bindings for curses are not fully capable of displaying the unicode-chars I decided to drop curses and shifted to urwid. Now I've got some basic questions in the matter of urwid and twisted. As you may know I'm using a mvc-pattern and I have not discovered a way to combine _and_ start urwid with twisted yet. Maybe someone who already worked with urwid can give me a small hint. Code: http://codepad.org/0Hlvmp1b class … [View More]

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[Twisted-Python] FTP LIST
by Simply for IT Dec. 28, 2008

Dec. 28, 2008

Hi Everyone, I just have started to study twistedmatrix in my spare time couple of weeks ago. I am satisfied with the books, but as they are very terse, and they are not really FTP related, I could not figure out how the FTP is working. I would like to be able to filter/modify the LIST(ing) process. Eg after list(ing) the result should not list any .py files even if they are there. I have tried to look after IFTPShell, but no success sofar. Here is a code snipplet from the "official" … [View More]

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[Twisted-Python] Question on logging.
by Shawn Church Dec. 28, 2008

Dec. 28, 2008

My problem is that PyAmf uses the standard Python logging module and twisted uses it's own logging module. I would like to have a single logging mechanism that can be specified via twistd. I would also like to have more control of the output of the twisted log. After googling and reading Glyph's essay on the logging module ( http://twistedmatrix.com/trac/wiki/TwistedLogging) I have came up with two solutions: 1) Simply configure the logging module with a logging.Handler subclass that … [View More]

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[Twisted-Python] A question about ITransport.write()
by Lian Cheng Dec. 28, 2008

Dec. 28, 2008

Hi, all As a Twisted newbie, I read the Twisted documentation, and found that: 1. ITransport.write() doesn't return a deferred. 2. IProtocol doesn't have a dataSent() callback or something alike. Since ITransport.write() is a non-blocking call, how can I be informed when data sent by ITransport.write() is actually sent successfully? Cheers Cheng

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com Dec. 28, 2008

Dec. 28, 2008

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[Twisted-Python] Compress/deflate support for getPage...
by Sam's Lists Dec. 24, 2008

Dec. 24, 2008

Is there any support for compress/deflate for webpages using the web client via getPage? If not, does anyone have a wrapper function before I make my own? Thanks

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[Twisted-Python] twisted.conch.ssh.session.SSHSession.request_subsystem
by Tzury Bar Yochay Dec. 23, 2008

Dec. 23, 2008

Hi all, I've managed to come up with a minimal sftp server implementation which able to auth users using rsa_key the code is available at: http://gist.github.com/37446 The point is that I am missing the knowledge needed in order to add path control. That is, controlling which path(s) a user can access. at http://twisted.conch.ssh.session.SSHSession.html#request_subsystem it appears to be undocumented Would love to get some references, samples, etc. Thanks in advance, Tzury

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[Twisted-Python] How is happened?
by biziap biziap Dec. 22, 2008

Dec. 22, 2008

I am trying to migrate to web2. And find the "OldRequestAdapter". What I did is callling: ## in a resource of web2 def render(self,web2_request): request = twisted.web2.compat.makeOldRequestAdapter(web2_request) File "c:\python25\Lib\site-packages\twisted\web2\compat.py", line 336, in getSession cookiename = string.join(['TWISTED_SESSION'] + self.sitepath, "_") AttributeError: 'OldRequestAdapter' object has no attribute 'sitepath'

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com Dec. 21, 2008

Dec. 21, 2008

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Re: [Twisted-Python] What to do when a service fails to start, also, deferred and startService
by Terry Jones Dec. 21, 2008

Dec. 21, 2008

Hi Glyph Thanks for the detailed reply. >>>>> "glyph" == glyph <glyph(a)divmod.com> writes: glyph> On 27 Nov, 05:16 pm, terry(a)jon.es wrote: glyph> For me, baroque and elaborate start-up dances are a code smell. glyph> Services should be as independent as possible. Of course, sometimes glyph> some kind of initialization conversation is unavoidable, but I do glyph> like to try to keep it as short as possible. I do too. Sometimes it takes (me at least) a … [View More]few iterations before you see how best to do that. glyph> I think you're misunderstanding what a "service" is. The word is, glyph> perhaps, a bit to lofty for its humble job. A service is just an glyph> event notification mechanism that tells you when it's time to start glyph> up, and when it's time to shut down. glyph> I can understand why it would be attractive to misunderstand in this glyph> way, though: IService doesn't do very much, you have requirements glyph> that it doesn't cover, and if it were the thing you understand it to glyph> be then it would cover those requirements. I'm sure that would be glyph> nicer for you :). glyph> This might seem a bit inconsistent, since stopService uses the glyph> return of a Deferred. However, this is for a very specific reason, glyph> not a generalized error-handling case: you may need to prevent the glyph> *rest* of the system (specifically, the reactor) from completely glyph> shutting down until you've managed to cleanly shut down whatever glyph> you're trying to shut down on potentially remote systems. glyph> startService has no such problem though; the service subsystem has glyph> told you "It's time to start up!" - its job is done, and the reactor glyph> isn't going away as part of service startup, so it's your glyph> responsibility as an application author to make sure your other glyph> dependencies are properly initialized. OK, this is helpful - I have been looking at it from a different point of view, as you've guessed. >> But if something does go wrong, you've got a failure propagating its way >> down a errback chain, eventually (unless an errback switches you back to >> the callback chain) popping out the end and causing the reactor to issue >> an Unhandled Error message. So you can't indicate that the service has >> failed to start by throwing, because the exception is going to pop >> harmlessly out the end of the deferred chain as a generic unhandled >> error and will not cause Twisted to know that the service couldn't >> start. glyph> The key question here is: indicate to whom? If you want to indicate glyph> it to some other object, well, try:except: or addErrback and call a glyph> method on that object. Nothing magic about it. I have code written as a Twisted plugin. So I have a class implementing IServiceMaker and IPlugin, and I create an instance of that class which gets found when I invoke twistd from the command line. So in my case I want to indicate to twistd that the service that my class creates a makeService method to create, but which I do not set in motion, has failed to start and that twistd should exit, or do something other than cheerfully tell me that there's been an Unhandled Error. Does that make more sense? Sorry, I should have said I was using twistd. glyph> In what way would you expect the service mechanism to "deal with" glyph> returning a Deferred? Stop starting other services? Print out some glyph> different log message? I'm not sure what should happen. I'm sitting at the command line, I've asked twistd to start something for me, there's clearly been a problem doing so (and this doesn't have to be baroque, maybe I just couldn't listen on a specific port I wanted, or maybe my code somehow raised an Exception), but I don't seem to have a mechanism for having twistd take any notice at all. I'm just talking about the case where startService calls something that returns a deferred and there's an Exception that comes back down the Deferred chain as a failure. I suppose if startService raises an Exception itself directly, something else happens - maybe twistd exits. glyph> IService is a very, very simple interface. If you want to respond glyph> to failures from startService (deferred failures, exceptions, or glyph> whatever else) in a useful way, then you can write your own glyph> implementation of it which manages startup order, keeps track of glyph> dependencies, and maintains a state machine that handles stopService glyph> appropriately if called in mid- startup. glyph> I don't think that having to implement an interface with 6 methods glyph> on it could be considered "cruel and unusual". If you think so you glyph> may want to investigate options other than Twisted: you will glyph> frequently be expected to implement interfaces with methods on them glyph> ;-). :-) glyph> There's no need to "track down and subclass" lots of things. Your glyph> IService wants the things that it contains to have a richer glyph> interface which allows for error handling, dependencies, and glyph> propagation, so simply write a single wrapper for simpler IService glyph> objects that expands the interface to do the other things that glyph> you're interested in. In the case of a service being started by twistd, it doesn't seem as simple as you describe, but maybe that's my lack of understanding again. I can easily subclass IService, but something else is calling the startService method of that subclass. And that thing, whatever it is, is not expecting me to return a deferred. So if my startService has for some reason got its hands on a deferred, it can't simply hand it back to its caller and have something (twistd in my case) see that an error occurred. It does feel like I have to track down what this something else might be. Either working from my IServiceMaker implementation or working from /usr/bin/twistd to find where startService is not trivial (you guys wrote it, I'm sure the logic is all much clearer to you). After looking through a few files I wind up at twisted/application/app.py, which has a startApplication function that calls service.IService(application).startService(). So I guess that's what is calling my startService. So I could make my own startApplication function, but I then have the same problem, I wind up with a deferred on my hands and my caller is not expecting me to return it. Plus, the startApplication function sits at the top level of twisted/application/app.py, so I have to find whatever is calling that. That seems to be twisted/scripts/_twistd_unix.py, which imports twisted.application.app and has a top-level startApplication that calls app.startApplication. But who is calling that? Looks like twisted/scripts/twistd.py is, and that's called by /usr/bin/twistd. So should I write my own twistd? All this doesn't seem to be a matter of simple subclassing. Plus, I can't just go in and start editing the top-level functions in twisted/application/app.py and twisted/scripts/_twistd_unix.py or code that imports app, etc. Sorry for so many questions - I really don't know if I'm missing something simple here. I do enjoy digging into all this, and I appreciate your apparently limitless patience. I wish I knew it all better. Twisted is complex and it's a pretty good bet that anything you think of or run into as a n00b has been thought of or encountered before, and that whatever way you think of to solve it will probably be non-optimal, or plain wrong, or in ignorance of a solution someone much more experienced has already implemented, or... etc. Hence my many questions. glyph> This all strikes me as totally straightforward and easy, and I don't glyph> think I'm any kind of super-genius for being able to write a few glyph> Python classes that call a few simple start/stop methods in the glyph> order that I want them to run in :). I should have mentioned that I want to use twistd. In fact I have something like a process pool running in one service and I talk to it from another machine. I say "hey, process pool, start me up the following service (a twistd service)" and I would then like to know if that service started, and if not then why not. So having twistd fail or report an error if it can't start a service would be useful. glyph> Doing either of those things would definitely be wrong. There's no glyph> reason to sys.exit or reactor.stop if your application can't start glyph> up, unless your management system specifically calls for such a glyph> thing. Maybe this is a case where it's (semi-)justified. At least if I called sys.exit the twistd process would go away, instead of sitting there acting as though nothing's wrong :-) I can also, of course, try interacting with the service I think I just started on the remote machine, and if I can't then I can tell the original process pool to kill the twistd process. But that seems a pretty roundabout alternative to just having twistd notice that something went awry when calling startService. glyph> In the future, even the Twisted plugin code might be starting some glyph> things in addition to your application. As I mentioned above, a glyph> good reason to do that is to perform diagnostics on failed startups glyph> :). I assume you really mean "startups" and not "services". In which case, I'm 100% sure there's something funny here, but I can't figure it out. I'd love to know, and I'm smiling broadly in any case. Too bad email loses so much humor..... we can always try though. Thanks again, Terry [View Less]

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Re: [Twisted-Python] how to get an idle callback while running a reactor?
by Andrew Francis Dec. 20, 2008

Dec. 20, 2008

Message: 6 Date: Sat, 20 Dec 2008 08:28:20 -0700 From: Joe Strout <joe(a)strout.net> Subject: Re: [Twisted-Python] how to get an idle callback while running a reactor? To: Twisted general discussion <twisted-python(a)twistedmatrix.com> Message-ID: <494D0F14.3000105(a)strout.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Hi Joe: >Well, the thing is that there will actually be a great many things that >could cause it to need to send a message, … [View More]such as the time, a change in >the outside temperature, a certain change in the value of a stock fund, >etc. And the AIM interface isn't the only interface to this bot. I would argue all these things can be viewed external events - even time (imagine a clock source is calling your system every N time units). In turn, your programme reacts to the external events. At a more concrete level, you have to ask yourself questions like "is my programme a client, a server (or both)? That is, is my programme making connections? Or is it waiting for connections? This will affect how you structure and start-up your application. From I see SkippyTalkBot is a client. >Now, that does suggest an alternative approach, which is to ignore >twisted's event/idle mechanisms and use something external to it. But >I'm also fairly newish to Python, so I'm not sure exactly how to do that >either -- reactor.run() is a blocking call, so I supposed I'd have to >use threads. Yes under the hood reactor.run() blocks. However the reactor is what effectively starts a Twisted application. I would argue that under most circumstances, you probably don't care that the reactor blocks because your application isn't doing anything until it receives an event from the reactor. As for threads. Off hand, I suspect you don't need threads ..... >But if there's a simple way to do this within Twisted, I'd like to learn >what that is Let us pretend your programme polls various network sources at regular intervals. So perhaps your code could look like: if __name__ == "__main__": # it may be helpful to keep track of the task objects source['source-a] = task.LoopingCall(callback-for-stockTicker, ...) source['source-b] = task.loopingCall(callback-for-thermostat, ...) source['source-c] = task.loopingCall(callback-for-timer, ....) for source in sources: source.start(someInterval, True | False) reactor.run() and each callback-for-X sets up the appropriate call to the remove source and its callback chain. # assume we are using SOAP def callback-for-stockTicker(): ticker = soap.Proxy(....) ticker.callRemote(....).addCallback().addErrback() Cheers, Andrew [View Less]

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[Twisted-Python] Mysql proxy in twisted ?
by Marc Byrd Dec. 20, 2008

Dec. 20, 2008

Hi, I was thinking of building a mysql proxy in twisted, wonder if there is already such a thing (not found on first coupla pages of google search), and if not, thoughts about building one. [BTW, I'm quite familiar with mysql-proxy - not thrilled w/ LUA scripting...] If anyone is interested in helping, I'm definitely thinking open source. Thanks, Marc

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[Twisted-Python] how to get an idle callback while running a reactor?
by Joe Strout Dec. 20, 2008

Dec. 20, 2008

I'm trying to make a simple AIM bot that, in addition to responding when I talk to it, can also send me a message on its own initiative. My code is based on SkippyTalkBot [1], but I confess that I don't understand it very well, and though I've been crawling the Twisted documentation for a few days now, it's still rather mysterious to me. So I'm at a loss as to how to add an "idle" function that will allow my bot to periodically see whether it has something new to say to the user. My … [View More]

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[Twisted-Python] Two thumbs up for inotify.py
by David Ripton Dec. 19, 2008

Dec. 19, 2008

I just tried the latest inotify.py from dialtone's sandbox, and I like it. My application is a little PyGTK / Cairo recording data scope (closed source) that needs to read lots of little files and plot lots of data points in realtime. I have my own inotify/ctypes wrapper (at the time I wrote it I found two Python inotify wrappers; one was GPL and the other didn't work for me) which works okay in this application. But it's a bit gross because my call to see if there are any inotify events … [View More]

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[Twisted-Python] Re: Pyjamas + web2py + twisted vs Django + Pinax (Cary Hull)
by Theron D. Huffman Dec. 19, 2008

Dec. 19, 2008

Thanks Cary, Where would Nevow/Athena fit in my strategy? 1, 2, 3 , or 4? Actually I have looked at Nevow/Athena and I'm very afraid of using it because there's only a few examples and a complete lack of documentation. Dan > > Message: 7 > Date: Thu, 18 Dec 2008 17:57:54 -0800 > From: "Cary Hull" <cary.hull(a)gmail.com> > Subject: Re: [Twisted-Python] Pyjamas + web2py + twisted vs Django + > Pinax > To: "Twisted general discussion" <twisted-python(a)… [View More]

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[Twisted-Python] reactor.spawnProcess cause error fatal: The remote end hung up unexpectedly
by Tzury Bar Yochay Dec. 19, 2008

Dec. 19, 2008

Hi, I've posted about it yesterday and now after digging bit more, I am more precise about the source of the errors I am receiving. In short, I am willing to deploy on my server an SSH daemon which I can control what commands can be executed, and by who. I started with samples found on the web and at Twisted docs, and continue from there. I only tried to run git commands over SSH so far and the weird thing is that it sometimes work, and sometimes not. e.g. I type: 'git clone ssh://localhost:… [View More]

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