[Python-Dev] patch: try/finally in generators

[Guido van Rossum]

> http://www.python.org/sf/584626
> 
> This patch removes the limitation of not allowing yield in the try part
> of a try/finally. The dealloc function of a generator checks if the 
> generator is still alive and resumes it one last time from the return 
> instruction at the end of the code, causing any try/finally blocks to be 
> triggered. Any exceptions raised are treated just like exceptions in a
> __del__ finalizer (printed and ignored).

I'm not sure I understand what it does.  The return instruction at the
end of the code, if I take this literally, isn't enclosed in any
try/finally blocks.  So how can this have the desired effect?

Have you verified that Jython can implement these semantics too?

Do you *really* need this?

--Guido van Rossum (home page: http://www.python.org/~guido/)