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Yield inside try...finally

W Isaac Carroll icarroll at pobox.com
Thu Jun 5 06:13:43 EDT 2003 
Jeremy Fincher wrote:
> I wonder if he's considered relaxing that restriction to allow at most
> *one* try: finally: block, or any number of try: finally: blocks whose
> finally: clauses are identical (which is effectively equivalent to a
> single finally: clause).  He could then just compile the finally code
> into an __del__ method on the generator-iterator.

I don't think it's that simple. For example:

     def finalgen():
         while not done:
             try:
                 foo = makefoo()
                 yield foo
             finally:
                 cleanup(foo)
             yield somethingelse

At the first yield statement, the generator would need a __del__ method 
that calls cleanup(foo). At the second yield statement, no __del__ 
method is needed because cleanup(foo) was called when the generator was 
resumed. Solving this problem, however, would lift your proposed 
restriction that only one finally block be allowed.

TTFN
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