I don't quite understand the behavior of lambdas in the following code:
from twisted.internet import reactor, defer
def someDeferred(val):
d = defer.Deferred()
reactor.callLater(1, d.callback, val)
return d
def done(result):
print "all done"
reactor.stop()
def twothing(i):
print "twothing: %s" % i
return i
def onething(result, i, callableThing):
print "onething: %s, result %s" % (i, result)
callableThing()
def dlistspawn():
dlist = []
values = [(1, 'one'), (2, 'two'), (3, 'three')]
for i, v in values:
deferred = someDeferred(i)
deferred.addCallback(onething, i, lambda: twothing(v))
dlist.append(deferred)
dl = defer.DeferredList(dlist)
dl.addCallback(done)
return dl
if __name__ == "__main__":
dlistspawn()
reactor.run()
Which produces:
onething: 1, result 1
twothing: three
onething: 2, result 2
twothing: three
onething: 3, result 3
twothing: three
all done
Why does the call to twothing() (via a lambda and callableThing)
always bind to 'three'? How do I change the code to get it to bind
successively to 'one', 'two', and 'three'?
Thanks,
Gary
