[Python-ideas] Proposal: Abolition of bare except clauses

[Chris Angelico]

On Sun, Apr 12, 2015 at 1:15 AM, Steven D'Aprano <steve at pearwood.info> wrote:
> On Sat, Apr 11, 2015 at 11:44:23PM +1000, Chris Angelico wrote:
>
>> Every document I've ever seen has taken one of two attitudes toward
>> old-style classes. Either they should be considered deprecated, and
>> every class you define should explicitly subclass something; or
>> they're a really cool micro-optimization with a few fancy
>> flexibilities that new-style classes don't have, but which come up
>> only in the most obscure cases.
>
> I wouldn't necessarily believe that classic classes are still faster
> than new-style classes. I think it was certainly true back in the 2.2
> and 2.3 days, but probably not in 2.7. In any case, I'd like to see the
> benchmarks demonstrating a speed advantage to classic classes before
> believing that they are an optimization in practice.

Not sure if there's a speed advantage or not, but apparently there's a
size advantage:

http://lucumr.pocoo.org/2014/8/16/the-python-i-would-like-to-see/

Though the difference doesn't apply to instances - a new-style class
instance is marginally smaller than its compatriot - and the
difference would be dwarfed by actual content anyway, in a typical
program. Hence "micro-optimization".

ChrisA