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<DIV> </DIV>
<DIV>Thank you very much.</DIV>
<DIV>I got it, I changed it to use a defer object, not
deferredlist</DIV>
<DIV> </DIV>
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<DIV><B>From:</B> <A
href="mailto:exarkun@twistedmatrix.com">exarkun</A></DIV>
<DIV><B>Date:</B> 2014-03-05 23:00</DIV>
<DIV><B>To:</B> <A href="mailto:twisted-python@twistedmatrix.com">Twisted
general discussion</A></DIV>
<DIV><B>Subject:</B> Re: [Twisted-Python] Using DeferredList, on the remote
method get parameter of None type?</DIV></DIV></DIV>
<DIV>
<DIV>On 02:35 pm, yangyouxiu@gmail.com wrote:</DIV>
<DIV>></DIV>
<DIV>>When developing server-client software, on the client i call the method
</DIV>
<DIV>>getTrafficDate, but on the server end, i got nio is </DIV>
<DIV>>None(d2=d.addCallback(lambda object: </DIV>
<DIV>>object.callRemote("getNIOTrafficInfo", node, nio)))</DIV>
<DIV>>,so, what's the key point?</DIV>
<DIV>></DIV>
<DIV>>[snip]</DIV>
<DIV>> for interface in
interfaces:</DIV>
<DIV>> nio=
</DIV>
<DIV>>self.interfacenio_dict[node]['interfaceinfo'][interface]</DIV>
<DIV>> if
nio is not None:</DIV>
<DIV>>
if 'nio_tap' in nio or 'NIO_NF_tap' in nio:</DIV>
<DIV>>
d= globals.perspective.callRemote('getServerRoot')</DIV>
<DIV>>
d2=d.addCallback(</DIV>
<DIV>>
lambda object:</DIV>
<DIV>>
object.callRemote("getNIOTrafficInfo", node, </DIV>
<DIV>>nio))</DIV>
<DIV>>[snip]</DIV>
<DIV> </DIV>
<DIV>The value of `nio` varies for each iteration of the loop. The value
of </DIV>
<DIV>`nio` isn't passed to the getNIOTrafficInfo remote method until the `d`
</DIV>
<DIV>Deferred fires - this will almost certainly be only after the loop </DIV>
<DIV>finishes (since it depends on network traffic which will only happen </DIV>
<DIV>after this method returns).</DIV>
<DIV> </DIV>
<DIV>So all of the remote calls will be made with whatever value `nio` has on
</DIV>
<DIV>the last iteration of the loop. This is just how scopes work in
Python. </DIV>
<DIV>Consider this simplified example:</DIV>
<DIV>>>>def foo():</DIV>
<DIV>... functions = []</DIV>
<DIV>... for i in range(3):</DIV>
<DIV>...
functions.append(lambda: i)</DIV>
<DIV>... for f in functions:</DIV>
<DIV>... print f()</DIV>
<DIV>...</DIV>
<DIV>>>>foo()</DIV>
<DIV>2</DIV>
<DIV>2</DIV>
<DIV>2</DIV>
<DIV>>>></DIV>
<DIV> </DIV>
<DIV>Jean-Paul</DIV>
<DIV> </DIV>
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