Mailman 3 April 2014 - Twisted

[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com 06 Apr '14

06 Apr '14

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[Twisted-Python] inlineCallbacks + raise exception behavior is different than deferred.errback
by Croepha 03 Apr '14

03 Apr '14

Hello: Please refer to the following script: import sys import twisted.internet.defer import twisted.internet.reactor import twisted.python.log print "Twisted version", twisted.version print "Python version", sys.version class ExceptionToRaise(Exception): pass exception_to_raise = ExceptionToRaise() @twisted.internet.defer.inlineCallbacks def icb_error_maker(): """ Raises an exception implemented as an inline inlineCallbacks """ raise exception_to_raise def pod_error_maker(): """ Raises an exception implemented as a plain old deferred """ deferred = twisted.internet.defer.Deferred() deferred.errback(exception_to_raise) return deferred #ERROR_MAKER_TO_USE = icb_error_maker ERROR_MAKER_TO_USE = pod_error_maker @twisted.internet.defer.inlineCallbacks def intermediate_function3(): print 'intermediate_function3 1' try: yield ERROR_MAKER_TO_USE() except BaseException as exception: print 'intermediate_function3 exception', repr(exception) raise print 'intermediate_function3 2' @twisted.internet.defer.inlineCallbacks def intermediate_function2(): print 'intermediate_function2 1' try: yield intermediate_function3() except BaseException as exception: print 'intermediate_function2 exception', repr(exception) raise print 'intermediate_function2 2' @twisted.internet.defer.inlineCallbacks def intermediate_function1(): print 'intermediate_function1 1' try: yield intermediate_function2() except BaseException as exception: print 'intermediate_function1 exception', repr(exception) raise print 'intermediate_function1 2' def run(): d = intermediate_function1() d.addErrback(twisted.python.log.err) d.addBoth(lambda n: twisted.internet.reactor.stop()) twisted.internet.reactor.callWhenRunning(run) twisted.internet.reactor.run() When ERROR_MAKER_TO_USE = icb_error_maker The output is as follows: Twisted version [twisted, version 13.2.0] Python version 2.7.3 (default, Feb 27 2014, 20:00:17) [GCC 4.6.3] intermediate_function1 1 intermediate_function2 1 intermediate_function3 1 intermediate_function3 exception ExceptionToRaise() intermediate_function2 exception ExceptionToRaise() intermediate_function1 exception ExceptionToRaise() Unhandled Error Traceback (most recent call last): File "/home/daveb/bzr_repo/player_rm2/test2/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1237, in unwindGenerator return _inlineCallbacks(None, gen, Deferred()) File "/home/daveb/bzr_repo/player_rm2/test2/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1099, in _inlineCallbacks result = g.send(result) File "icb_error_test1.py", line 52, in intermediate_function2 yield intermediate_function3() File "/home/daveb/bzr_repo/player_rm2/test2/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1237, in unwindGenerator return _inlineCallbacks(None, gen, Deferred()) --- <exception caught here> --- File "/home/daveb/bzr_repo/player_rm2/test2/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1099, in _inlineCallbacks result = g.send(result) File "icb_error_test1.py", line 37, in intermediate_function3 yield ERROR_MAKER_TO_USE() File "/home/daveb/bzr_repo/player_rm2/test2/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1228, in unwindGenerator gen = f(*args, **kwargs) File "icb_error_test1.py", line 19, in icb_error_maker raise exception_to_raise __main__.ExceptionToRaise: However when ERROR_MAKER_TO_USE = pod_error_maker The output is as follows: Twisted version [twisted, version 13.2.0] Python version 2.7.3 (default, Feb 27 2014, 20:00:17) [GCC 4.6.3] intermediate_function1 1 intermediate_function2 1 intermediate_function3 1 intermediate_function3 exception ExceptionToRaise() intermediate_function2 exception ExceptionToRaise() intermediate_function1 exception ExceptionToRaise() Unhandled Error Traceback (most recent call last): Failure: __main__.ExceptionToRaise: Questions: 1. Why is it that icb_error_maker raises an exception that retains its traceback while pod_error_maker does not? 2. How might one retain the inlineCallback trace when handling Exceptions/Failures from deferreds? (I would prefer a universal method, ie not doing a Try/Reraise at every yield point) ? 3. I have taken a look at the code in twisted/internet/defer.py and I am not sure where the distinction between inlineCallback exceptions and deferred errors are being made. Would someone please elaborate on this process. Thanks

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[Twisted-Python] IFinishableConsumer in twisted.protocols.ftp.IFinishableConsumer
by Adi Roiban 03 Apr '14

03 Apr '14

Hi, Reading the producer/consumer docs I first found out that IFinishableConsumer api link is broken (link to twisted.internet.interfaces): http://twistedmatrix.com/documents/current/core/howto/producers.html#auto7 Then I found out that IFinishableConsumer is defined in twisted.protocols.ftp.IFinishableConsumer I was expecting to see the interface defined in twisted.internet.interfaces . Should the broken link be fixed or interfaced moved ? I think that moving the interface should be safe, as old imports will still work. Thanks! -- Adi Roiban

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[Twisted-Python] Using twisted for a smtp dialog
by Grigorescu Ciprian 02 Apr '14

02 Apr '14

Hello, I am new in twisted world and I am struggle to understand it. I am trying to create a smtp connection and initiate a smtp dialog: helo, mail from, rcpt, for a list of address, and catch the answer from the smtp server Can anyone point me the right direction, where to start? Thanks a lot, Grig

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[Twisted-Python] Using cred, how to prevent the user repeat-login?
by yangyouxiu 02 Apr '14

02 Apr '14

In my Client-Server Application,I do not want two user login with the same login name. For example, user1 logined with name "test1",then user2 try to login with "test1" too, the login of user2 should be denied. At now, my code could not achieve this goal,so what's the method. Thanks all! The following is server code: ----------------------------------------------------------------------------- class simulationServer: def __init__(self): self.groups = {} # indexed by name self.groups['#admin']= Group('#admin') self.groups['#general']=Group('#general') def joinGroup(self, groupname, user): if groupname not in self.groups: self.groups[groupname] = Group(groupname) self.groups[groupname].addUser(user) return self.groups[groupname] def leaveGroup(self, groupname, user): self.groups[groupname].delUser(user) return self.groups[groupname] def getGroup(self, admin=False): if admin==True: return self.groups['#admin'] return self.groups['#general'] class simulRealm: implements(portal.IRealm) def requestAvatar(self, avatarID, mind, *interfaces): assert pb.IPerspective in interfaces avatar = User(avatarID) avatar.server = self.server avatar.attached(mind) return pb.IPerspective, avatar, lambda a=avatar:a.detached(mind) class User(pb.Avatar): def __init__(self, name): self.name = name self.group=None self.status=False #False: general client user not sync yet self.serverRoot=ServerRoot() def attached(self, mind): self.remote = mind def detached(self, mind): print '%s detached...'%self.name self.server.leaveGroup(self.group, self) self.server.messageClientUserupdated() self.remote = None def perspective_joinGroup(self, groupname): print 'joined Group on Server Machine ' print groupname self.group=groupname self.server.joinGroup(groupname, self) self.server.messageClientUserupdated() return groupname def perspective_getServerRoot(self): return self.serverRoot def getClientRoot(self): return self.remote def perspective_updateStatus(self): self.status=True # user sync class Group(pb.Viewable): def __init__(self, groupname): self.name = groupname self.users = [] def addUser(self, user): self.users.append(user) def delUser(self, user): self.users.remove(user) def getallUsers(self): return self.users def getnotSyncUsers(self): nosyncusers=[] if self.users: for user in self.users: if not user.status: nosyncusers.append(user) return nosyncusers def getUsers(self): syncusers=[] if self.users: for user in self.users: if user.status: syncusers.append(user) return syncusers ----------------------------------------------------------------------------- Client code: def1 = factory.login(credentials.UsernamePassword(self.group+'_'+self.UserNameandPwd[0], self.UserNameandPwd[1]), client=self) def1.addCallback(self.connected) def1.addErrback(self.connectFailure)

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[Twisted-Python] enabling spam filtering on trac
by Glyph 01 Apr '14

01 Apr '14

Hi all, We've been having a spate of spammy comments on twistedmatrix.com lately. To my pleasant surprise I discovered that someone had installed, and even configured, a spam filtering plugin, but it was configured to do absolutely nothing. I think I've got it set up right now, but the UI to do so is a bit confusing (there are point values for things and it's not clear how scoring works); if anyone gets a comment rejected for spamming, I'd like to know about it so I can adjust things. Thanks, -glyph

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