Mailman 3 May 2014 - Twisted

[Twisted-Python] Twisted.email.smtp Module ERROR
by VENKTESH GUTTEDAR May 29, 2014

May 29, 2014

Hello, i have written a script to send email by using the twisted smtplib in which i am trying to import the ESMTPSenderFactory from twisted.mail.smtp. but its giving the error as import error : no module name mail.smtp. so please someone help me to get rid of this error. i am using python 2.7 in ubuntu 13.10. thank you. -- Regards : Venktesh Guttedar.

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[Twisted-Python] Code question - semantic meaning of IServiceCollection(parent, parent)
by Jonas Brunsgaard May 26, 2014

May 26, 2014

Hello all Will someone explain to me what happens when you call an Interface with arguments, and why the same argument twice? My problem is to understand the semantics of the line parent = IServiceCollection(parent, parent) part of def setServiceParent(self, parent): if self.parent is not None: self.disownServiceParent() parent = IServiceCollection(parent, parent) self.parent = parent self.parent.addService(self) in twisted.application.service Thanks in advance.

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[Twisted-Python] Importing reactor changes PATHs?
by Merovingian May 26, 2014

May 26, 2014

Hello, Python 2.7.5 32 bit on Windows. Twisted 13.2.0 import ctypes dll = ctypes.CDLL("ssleay32.dll") Loads dll from the current folder import ctypes from twisted.internet import reactor dll = ctypes.CDLL("ssleay32.dll") Loads dll from Python27\lib\site-packages\OpenSSL How so? How can I prevent reactor from changing the PATH (or whatever it's changing)?

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com May 25, 2014

May 25, 2014

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[Twisted-Python] doWrite called on a twisted.internet.unix.Port
by Killian De Smedt May 23, 2014

May 23, 2014

Hello everybody, I sometimes see the following error logged by a twisted application, it only happens sporadically and I cannot even reproduce when trying to re-execute the exact sequence of those failures. So giving an SSCCE is quite impossible for now (sorry). Given this trace it's also hard to find what was actually called/executed. Unhandled Error Traceback (most recent call last): File "/path/to/twisted.zip/twisted/python/log.py", line 88, in callWithLogger File "/path/to/twisted.zip/twisted/python/log.py", line 73, in callWithContext File "/path/to/twisted.zip/twisted/python/context.py", line 118, in callWithContext File "/path/to/twisted.zip/twisted/python/context.py", line 81, in callWithContext --- <exception caught here> --- File "/path/to/twisted.zip/twisted/internet/posixbase.py", line 619, in _doReadOrWrite File "/path/to/twisted.zip/twisted/internet/base.py", line 1117, in doWrite exceptions.RuntimeError: doWrite called on a twisted.internet.unix.Port I cannot reproduce the scenario where this goes wrong, in the application there is only a single unix socket which is handled as follows: class cmd_protocol(basic.Int32StringReceiver): def stringReceived(self, command): self.factory.callback(command, self.send_response) def send_response(self, code, message): self.sendString(response_msg(result_code = code, message = message).SerializeToString()) //response_msg is a google protobuf class class cmd_factory(protocol.ServerFactory): protocol = cmd_protocol def __init__(self, callback, *args, **kwargs): self.callback = callback class cmd_server(object): def __init__(self, socket_file, callback, delete_previous_socket = True): if delete_previous_socket: try: os.remove(socket_file) except OSError: pass reactor.listenUNIX(socket_file, cmd_factory(callback)) #@UndefinedVariable Does anybody have any idea what could trigger the doWrite internally or how I at least I can start debugging this? Thank you, Killian

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[Twisted-Python] Porting Twisted to Python 3.
by Maxim Lacrima May 22, 2014

May 22, 2014

Hello! I can see that Python 3 support in Twisted is incomplete. I was able to `pip install twisted` on Python 3, but I couldn't run a simple example program using Twisted Agent. A simple `from twisted.web.client import Agent` causes `ImportError: No module named 'twisted.python.systemd'` I would like to help in porting Twisted to Python 3. I have a couple of questions. My initial idea was to run some twisted tests with trial and start from there. But it looks like trial is not ported to python3 and also I think many tests themselves are not python3 aware. So what is a recommended workflow? As for Twisted Agent... URL and its parsed components are now bytes, but `Agent._getEndpoint` operates on str, and so do other functions (`isIPAddress`, `isIPv6Address`), causing type and other errors. I would like to fix this (at least to try), but I need some guidance. Thank you. -- Regards, Maxim

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[Twisted-Python] IOpenSSLClientConnectionCreator was ContextFactory, now it's IOpenSSLClientConnectionCreator not ContextFactory
by exarkun＠twistedmatrix.com May 20, 2014

May 20, 2014

Hello, I just noticed that #7098 expanded the meaning of the objects Twisted typically refers to as "context factories". Prior to #7098, these were things that implemented a `getContext` method that returned an `OpenSSL.SSL.Context` instance. Subsequent to #7098, these are now *either* that or an object that provides `IOpenSSLClientConnectionCreator`. It seems that parts of Twisted itself were updated to reflect this change. For example, the very bottom of the TLS implementation stack in Twisted, `twisted.protocols.tls`, acknowledges this change (I imagine this was unavoidable). Also, way on the other side of Twisted, `twisted.web.client.Agent` takes advantage of this change to implement the great new certificate and hostname validation features introduced in 14.0.0. However, other parts of Twisted itself were not updated. For example, the layers that sit in between `twisted.protocols.tls` and `twisted.web.client.Agent` weren't touched much. `SSL4ClientEndpoint`, for example, still documents its `sslContextFactory` as "SSL Configuration information as an instance of L{twisted.internet.ssl.ContextFactory}.". And, somewhat insanely I think, `IReactorSSL.connectSSL` still says "@param contextFactory: a L{twisted.internet.ssl.ClientContextFactory} object.". Merely from a documentation standpoint, this seems suboptimal. From a compatibility standpoint... Well, it seems incompatible to me. Perhaps this is an instance where the compatibility policy can be broken (though really that's academic since 14.0.0 has already been released, the policy has been broken already) but I don't recall any explicit discussion about a decision to do this. I *hope* and suspect there won't be much fall-out from this change considering it's hard to implement TLS and as far as I know there are no third-party implementations of `IReactorSSL` (GNUTLS came to mind but they have their own incompatible interface afaict). In other words, maybe we'll get lucky this time. I wrote this email instead of filing tickets about the documentation problems because doing the latter was implicit acknowledgement that this incompatible change is okay. Having written the email now, I see there's probably no going back, regardless. Maybe we can learn something from this incident and avoid repeating it with a more popular interface, though. We could probably add a description of this particular kind of incompatible change to the `CompatibilityPolicy` wiki page. If reviewers read that page, then they'll know to watch out for it. And of course (assuming we're committed to this direction, which we seem to be) we need to fix the rest of the "contextFactory" documentation throughout Twisted. I'll go file one ticket related to that now... Jean-Paul

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[Twisted-Python] [ANN] thimble 0.1.0
by Laurens Van Houtven May 20, 2014

May 20, 2014

Hi everyone! thimble is a library that makes it easy to wrap blocking objects with a thread pool to give you an async API. In particular, it lets you selectively wrap blocking methods, and takes an explicit reactor and thread pool, making it at least slightly harder to do the obvious but potentially bad thing and tricky to test thing (global reactor state, using the reactor thread pool). (It's a thimble because it lets you play with threads without pricking yourself :-)) This is a small library: it doesn't really fix any big engineering problems, and that's okay. It just removes a bunch of boilerplate I've seen in many a Twisted software project, usually boilerplate that's implemented using the suboptimal methods described above. The README should run you through it real quick: https://pypi.python.org/pypi/thimble This is just an early release. I expect that the documentation isn't good enough to get best practices out the door, particularly in setting up thread pools. I think it's pretty decent and probably already worth a look, though :-) Thanks to Rackspace for letting me write it open source & on company time :-) hth lvh

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[Twisted-Python] Why would someone need SSHTransportAddress?
by Adi Roiban May 19, 2014

May 19, 2014

This email is bases on comment from https://twistedmatrix.com/trac/ticket/5999 I fail to see the reason why SSHTransportAddress exist and why would anyone need It. SSHTransportAddress is an IAddress which has a single member called "address" and which is an IAddress ... In case SSHTransportAddress is useful and people should start using it, maybe this is a bug in SSHTransportAddress documentation as it should stat why someone want to use it instead of directly using any address define in twisted.internet.address SSHTransportAddress was introduced in this ticket https://twistedmatrix.com/trac/ticket/2997 and since it was reviewed and approved by 2 other persons, I guess that I am the only one failing to understand to purpose of this class. Thanks! -- Adi Roiban

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com May 18, 2014

May 18, 2014

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