[Python-Dev] exec/with thunk-handling proposal

[Aahz]

On Mon, Feb 03, 2003, holger krekel wrote:
>
>     def __enter__(self):  
>         "before suite start"
> 
>     def __except__(self, type, value, tb): 
>         "swallow given exception, reraise if neccessary"
> 
>     def __leave__(self):
>         """upon suite finish (not called if __except__ 
>            exists and an exception happened)
>         """

No, __leave__/__exit__ should always be called regardless of whether an
exception hits.  That's the whole point of this proposal, IMO.

> One remark (mainly to Michael as he does that other 
> patch) about the hook-name __leave__ versus __exit__.
> we may want to eventually allow 'yield' within the
> thunk and then '__exit__' would be misleading.  Here is
> the use case:
> 
>     exec self.mylock:   # would lock/unlock on entering/leaving 
>                         # the generator
>         ...
>         for whatever in something:
>             yield whatever  
>         ...

I'm thinking that this is *way* too complex.  If you want something like
that, code it like this:

    for whatever in something:
        exec self.mylock:
            new_whatever = process(whatever)
        yield new_whatever
-- 
Aahz (aahz@pythoncraft.com)           <*>         http://www.pythoncraft.com/

"Argue for your limitations, and sure enough they're yours."  --Richard Bach