[Python-ideas] Proposal: Moratorium on Python language changes

Yuvgoog Greenle ubershmekel at gmail.com
Fri Oct 23 09:46:52 CEST 2009

On Fri, Oct 23, 2009 at 5:50 AM, Guido van Rossum <guido at python.org> wrote:
> You keep stressing the opportunities for new features, but I want to
> crush that hope
> [ snip ]
> Go invent a new language (and hope for it
> to become popular :-) if you want to experiment.

Crushing hope and pointing people to the door is ugly [*].

Why freeze? Instead, define how change occurs and make it as slow as
you like. Define the python kilo (1000x) development cycle. For
example the "moratorium" could state:

S&B = syntax and builtins

Python only introduces syntax and builtins once every X years[**] and
only in major version changes. Between pyNk releases S&B are locked.
New S&B can and should be tested on the next major revision's
experimental branch(es). New S&B will only be considered for inclusion
during the 2 years prior a pyNk major version.

If a core language feature is to be accepted it needs:
1. A community tested and reviewed patch
2. A migration strategy (ie 3to4 code).
3. Python-dev acceptance (which can only be applied for during the 2
year S&B period).

I suggest a new mailing list titled "python-experimental" for
discussion and development of experimental branches. Also, commit
privileges should be really common and easy to get for this branch of
branches. Mercurial could help in implementing this. I realize that
anyone can take the python source and do whatever they want on any
free source host but having an official lab[***] for this can give
another step between code that's in the wild and code that's in an
official (non-experimental) branch and thus save core developer's


[*] Beautiful is better than ugly.
[**] There were about 8 years between python 2 and python 3,
extrapolating from the discussion that this was too fast, lets say
X=10, sound reasonable?
[***] I prefer to call it a "playground" but now that python's all
serious business and not a language for fun I don't know how well that
would go.

ps (short for pike shedding) - the "moratorium" has an evil sound to
it. All python needs is a Core-Feature-Development-Cycle-Roadmap or
something catchier.

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