launchpad-dev team mailing list archive

[Jeroen Vermeulen <jtv@xxxxxxxxxxxxx>]

Barry Warsaw wrote:

> > it doesn't scale well for more than resource;
> 'one'?------------------------------^
Indeed.


>     >>> with open('/etc/passwd') as a, open('/etc/group') as b:
>     ...     pass
That's very good news!  And this presumably takes care of the "what if 
the second open() fails" and "what if b's cleanup depends on a being 
there" corner-case stuff.  At this point it's not longer the thin layer 
of sugar I had listed as an irrelevant gripe.

> I'm not sure the with-statement was designed for transactions, but one good
> reason why it shouldn't be used for transactions is because (IME) proper
> handling doesn't fit into pure try/finally:
We're in full agreement there.  The reason I seized on this is that I 
saw transaction handling documented on the python site as the main 
justifying use-case for the exception-handling design.
So I still say: by all means use it, but let's stay away from 
exception-dependent and exception-eating exit handlers for as long as we 
can!

Jeroen