[Python-Dev] PEP 463: Exception-catching expressions

[Antoine Pitrou]

On Sat, 22 Feb 2014 02:52:59 +1100
Chris Angelico <rosuav at gmail.com> wrote:

> On Sat, Feb 22, 2014 at 1:34 AM, Brett Cannon <brett at python.org> wrote:
> > While I like the general concept, I agree that it looks too much like a
> > crunched statement; the use of the colon is a non-starter for me. I'm sure
> > I'm not the only one whose brain has been trained to view a colon in Python
> > to mean "statement", period. This goes against that syntactic practice and
> > just doesn't work for me.
> >
> > I'm -1 with the current syntax, but it can go into the + range if a better
> > syntax can be chosen.
> 
> We bikeshedded that extensively on -ideas. The four best options are:
> 
> value = (expr except Exception: default)

-0.5

> value = (expr except Exception -> default)

-0.5

> value = (expr except Exception pass default)

-1 (looks terribly weird)

> value = (expr except Exception then default)

+0.5
But I'm aware it requires reserving "then" as a keyword, which might
need a prior SyntaxWarning.

Regards

Antoine.