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DeferArgs 0.3 by Example

DeferArgs 0.3, just a few hours after 0.2, is now released here. The only update is support for attemp/catch-all blocks without any @catch(type) handlers. In response to some people in #twisted@irc.freenode.net, here are examples that show what can be done more clearly.

To write any function that can accept deferred arguments nicely:

@deferargs
def printArgs(*args, **kwargs):
print args
print kwargs


To add psuedo-exception handlers and a psuedo-finally block to a @deferargs decorated function:

@deferargs
def printArgs(*args, **kwargs):
print args
print kwargs
print "This one is important! ", kwargs['important']
@catch(KeyError)
def onKeyError(e):
print "There was no important kwarg!"
@catch()
def onAnyError(e):
print "Crap!"
@cleanup()
def _(r):
print "Every thing is done."


There is also a model for a psuedo-try block, which basically decorates just calls the function immediately when you define it and its catch/cleanup handlers:

@attempt
def this():
assert False
@cleanup
def _(r)
print "And thats it."

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