[Python-Dev] The current dict is not an "OrderedDict"

[Antoine Pitrou]

On Wed, 8 Nov 2017 13:07:12 +1000
Nick Coghlan <ncoghlan at gmail.com> wrote:
> On 8 November 2017 at 07:19, Evpok Padding <evpok.padding at gmail.com> wrote:
> > On 7 November 2017 at 21:47, Chris Barker <chris.barker at noaa.gov> wrote:  
> >> if dict order is preserved in cPython , people WILL count on it!  
> >
> > I won't, and if people do and their code break, they'll have only themselves
> > to blame.
> > Also, what proof do you have of that besides anecdotal evidence ?  
> 
> ~27 calendar years of anecdotal evidence across a multitude of CPython
> API behaviours (as well as API usage in other projects).
> 
> Other implementation developers don't say "CPython's runtime behaviour
> is the real Python specification" for the fun of it - they say it
> because "my code works on CPython, but it does the wrong thing on your
> interpreter, so I'm going to stick with CPython" is a real barrier to
> end user adoption, no matter what the language specification says.

Yet, PyPy has no reference counting, and it doesn't seem to be a cause
of concern.  Broken code is fixed along the way, when people notice.

Regards

Antoine.