[Twisted-Python] running code on its own and importing, howto install a different reactor?
hi, i ran into this issue, i can run the code on its own "python working_code.py", but i cant import it...how do you fit the reactor in this scenario? python main_code.py Unhandled error in Deferred: Traceback (most recent call last): File "/home/julius/.local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1274, in unwindGenerator return _inlineCallbacks(None, gen, Deferred()) File "/home/julius/.local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1128, in _inlineCallbacks result = g.send(result) File "/home/julius/code/python/qt5-python2.x/example/working_code.py", line 7, in print_it arg = yield terrific_method() File "/home/julius/.local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1274, in unwindGenerator return _inlineCallbacks(None, gen, Deferred()) --- --- File "/home/julius/.local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1128, in _inlineCallbacks result = g.send(result) File "/home/julius/code/python/qt5-python2.x/example/working_code.py", line 14, in terrific_method reactor.callLater(2, d.callback, 2) exceptions.NameError: global name 'reactor' is not defined cat main_code.py import qt5reactor qt5reactor.install() from twisted.internet import reactor from working_code import print_it print_it() cat working_code.py from twisted.internet.defer import inlineCallbacks, Deferred, returnValue @inlineCallbacks def print_it(): arg = yield terrific_method() print arg @inlineCallbacks def terrific_method(): d = Deferred() reactor.callLater(2, d.callback, 2) result = yield d returnValue(result) if __name__ == '__main__': import qt5reactor qt5reactor.install() from twisted.internet import reactor reactor.callWhenRunning(print_it) reactor.run() ___ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
Re: [Twisted-Python] running code on its own and importing, howto install a different reactor?
Looks like the problem is that the twisted.internet.reactor is imported inside a block guarded by if __name__ == '__main__' When you import working_code that block doesn't run, because of the guard, so terrific_method tries to access "reactor" which doesn't exist. I guess your question is really how to get access to the reactor in working_code.py, since you can't import it in the top level namespace because you have ti install the qt5reactor *before* importing twisted.internet.reactor (right?). I don't know if there's a generally advised way of handling this, but I would simply put all the stuff in the guarded block in its own file and make sure to install the qt5reactor before importing anything else. ___ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
Re: [Twisted-Python] running code on its own and importing, howto install a different reactor?
I think the "recommended" way to get access to a reactor instance is to pass it in to methods that require it. While this can sometimes seem tedious it a) helps testing (because now you can easily pass a fake reactor object like Clock or a Mock instance) and b) shows you (and your users) which methods are (or might-be) async. So, try a signature like "def terrific_method(reactor):" instead. Now when you're writing tests, you can do this: fake_reactor = Clock() d = terrific_method(fake_reactor) fake_reactor.advance(2) # etc. -- meejah ___ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
Re: [Twisted-Python] running code on its own and importing, howto install a different reactor?
On Fri, 2016-07-29 at 23:11 +0400, meejah wrote: > I think the "recommended" way to get access to a reactor instance is to > pass it in to methods that require it. > > While this can sometimes seem tedious it a) helps testing (because now > you can easily pass a fake reactor object like Clock or a Mock instance) > and b) shows you (and your users) which methods are (or might-be) async. > > So, try a signature like "def terrific_method(reactor):" instead. Now > when you're writing tests, you can do this: > > fake_reactor = Clock() > d = terrific_method(fake_reactor) > fake_reactor.advance(2) > # etc. > Ah yes, you answered a question of mine not so long ago earlier and told me exactly thatsorry forgot. workig example if anybody ever digs this out: i modified the code like this: working_code.py from twisted.internet.defer import inlineCallbacks, Deferred, returnValue @inlineCallbacks def print_it(reactor): arg = yield terrific_method(reactor) print arg @inlineCallbacks def terrific_method(reactor): d = Deferred() reactor.callLater(2, d.callback, 2) result = yield d returnValue(result) if __name__ == '__main__': import qt5reactor qt5reactor.install() from twisted.internet import reactor reactor.callWhenRunning(print_it, reactor) reactor.run() main_code.py: import qt5reactor qt5reactor.install() from twisted.internet import reactor from working_code import print_it print_it(reactor) reactor.run() now on to some tests... ___ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
Re: [Twisted-Python] running code on its own and importing, howto install a different reactor?
steven meier writes: > if __name__ == '__main__': > import qt5reactor > qt5reactor.install() > from twisted.internet import reactor > reactor.callWhenRunning(print_it, reactor) > reactor.run() For "client-style" things (I guess I just mean "something that exits"), there's even a utility function that calls some method you provide with the reactor as the first argument, and arranges for reactor.stop() to get called exactly once (when the Deferred returned by your method fires). import qt5reactor qt5reactor.install() from twisted.internet.task import react if __name__ == '__main__': react(print_it) -- meejah ___ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
