Mailman 3 December 2012 - Twisted

[Twisted-Python] twisted logo use?
by meejah＠meejah.ca Dec. 10, 2012

Dec. 10, 2012

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Is this an acceptable (ab)use of the twisted logo? I can't find anything obvious on twistedmatrix.com about this sort of thing. More information about txtorcon is at https://txtorcon.readthedocs.org thanks, meejah -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Processed by Mailcrypt 3.5.8 <http://mailcrypt.sourceforge.net/> iQEcBAEBAgAGBQJQxO+XAAoJEMJgKAMSgGmnRzcH/1Pmo9OwQ4OTDGmTHvPARqER 2FH4noSwgULpNclIB58QEKlkbfCA1yFpZwMUj2dKtnGEz8kxwl1R3TPnjisSRs1f 5qXIaGg1uKAlCW0re2/xzp9GQCDzX3HfUkw7/GVs4nkASJOMAauUA2YMFd3+J430 oxPQUrmVHDnsw4pKMgRtWCv3gpySrBbNMvis0cc2CjNWpDtfSZX/+wtOjDN3oTII OBWp8yG/hR21TdBrmwJ7RLqFN3Cnpqyu8PATkyKMdyGLlXHf1jhaswJ/8OY15iAN rj5iZQPndMfgeVcj0TjGmJtqfOdtd+2ooFkPkr1Ge6zHo7irmvbNnYcJeNaB+7c= =G/88 -----END PGP SIGNATURE-----

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[Twisted-Python] Limiting the number of connections
by Miha Valencic Dec. 9, 2012

Dec. 9, 2012

Hi! I have developed a simple twisted tcp server which does ldap lookups as a result of user input. I would like to limit the number of connections each listener (I have 4, each on its own port) accepts. I guess people usually want to accept as many connections as possible, but I would like to limit them. >From what I've read (a single post from 2009): "As you observed, doing this on the server accepts and then immediately closes the connection. There is no way to not accept the connection. This is a limitation of the underlying platform APIs." Is this still the case? We can't limit the number of accepted connections? Regards, Miha.

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com Dec. 8, 2012

Dec. 8, 2012

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[Twisted-Python] inlineCallbacks loses custom exception type?
by Benjamin Rutt Dec. 7, 2012

Dec. 7, 2012

Hi, I am hitting an issue with inlineCallbacks-decorated functions. It seems that from within an inlineCallbacks-decorated func, if you yield on another deferred-returning func, and that deferred-returning func returns a deferred which will errback with a Failure wrapping a user defined exception type, then the user defined exception gets repackaged as a common Exception by the time you are in the inlineCallbacks-decorated function. It seems to be related to the fact that inside an inlineCallbacks-decorated func, if you yield on a func, and that func returns a deferred which errs back, twisted will convert the errback into a synchronous exception that it raises for you. That’s all a bit wordy, so maybe some code will help clarify: $ cat inlinecallbacks-loses-exception-types.py #!/usr/bin/env python import sys, traceback from twisted.internet import defer, reactor class MyException(Exception): pass def go2(): "An ordinary deferred-returning function that will return a deferred which is ready to errback()" try: raise MyException('xyz') except Exception as e: return defer.fail() # errs back with current exception context return defer.succeed(1) # unreachable code @defer.inlineCallbacks def go_inlinecb(): try: x = yield go2() print 'no exception raised' except MyException as e: print 'got my custom exception' traceback.print_exc() except Exception as e: print 'got a garden variety exception' traceback.print_exc() def go_noinlinecb(): d = go2() def cb(data): print 'got data in cb: %s' % (data) def eb(failure): try: failure.raiseException() except MyException as e: print 'got my custom exception' traceback.print_exc() except Exception as e: print 'got a garden variety exception' traceback.print_exc() d.addCallbacks(cb, eb) if sys.argv[1] == 'inline': reactor.callWhenRunning(go_inlinecb) elif sys.argv[1] == 'noinline': reactor.callWhenRunning(go_noinlinecb) reactor.callLater(2, reactor.stop) reactor.run() $ ./inlinecallbacks-loses-exception-types.py inline got a garden variety exception Traceback (most recent call last): File "./inlinecallbacks-loses-exception-types.py", line 21, in go_inlinecb x = yield go2() Exception: xyz $ ./inlinecallbacks-loses-exception-types.py noinline got my custom exception Traceback (most recent call last): File "./inlinecallbacks-loses-exception-types.py", line 36, in eb failure.raiseException() File "/sw/external/twisted-py27-11.0.0/lib/python/twisted/python/failure.py", line 338, in raiseException raise self.type, self.value, self.tb MyException: xyz So as you can see, it seems that if you use inlineCallbacks, you cannot ‘except MyException’ and catch your own custom exceptions. Somehow a generic Exception is constructed. Is there any workaround or is this a known issue? Thanks, -- Benjamin Rutt

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[Twisted-Python] Download instructions for twisted and ActiveState Python
by Craig Rodrigues Dec. 6, 2012

Dec. 6, 2012

Hi, At some of the Twisted Sprints in San Francisco, I found that on my Windows laptop, it was easy to set things up Twisted quickly by using the ActiveState Python package manager (pypm). I wrote some notes for doing this at: http://home.comcast.net/~rodrigc/python/twisted_install.html Rather than keep that info on my own web page, I thought it would be nice to contribute the information back to the Twisted wiki. This would not be the official way of installing Twisted on Windows, but would be some helpful information for an alternative way to install things on Windows. Since I do not have wiki edit permissions, I made a patch to http://twistedmatrix.com/trac/wiki/Downloads . If someone could help get this info on the wiki that would be great. -- Craig Rodrigues rodrigc(a)crodrigues.org

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com Dec. 1, 2012

Dec. 1, 2012

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