[Python-Dev] PEP 343 rewrite complete

[Guido van Rossum]

[Guido van Rossum]
> >   http://www.python.org/peps/pep-0343.html

[Phillip J. Eby]
> Looks great.  A few questions/comments:
> 
> * What's the rationale for raising TypeError from close()?  Wasn't
> RuntimeError discussed previously for that role?  (and it's also used by
> the with_template example)  OTOH, maybe that means we want a
> ControlFlowError or some such that can be used for both.

I really don't want a new exception for this, since it's just a bug in
the generator's code. I could go with RuntimeError here too, but I
figured TypeError's meaning in a wider sense applies: the generator
doesn't respond appropriately to the throw() call, which is similar to
not handling a particular argument (list) correctly.

> * The "opening" example under "Generator Decorator" seems to be missing a
> try/finally block.

Good catch. I've fixed this in the PEP.

> * The transaction handler could also be written as:
> 
>      @with_template
>      def transactional(db):
>          db.begin()
>          try:
>              yield db
>          except:
>              db.rollback()
>          else:
>              db.commit()
> 
> at least, if I understand it correctly.

Ah, of course. I've updated the PEP.

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