[Python-Dev] Backporting PEP 414

[Chris McDonough]

On Tue, 2012-02-28 at 16:48 -0500, Barry Warsaw wrote:
> On Feb 28, 2012, at 03:54 PM, Benjamin Peterson wrote:
> 
> >> If there is already a FAQ entry feel free to point me to it, but I would
> >> still be curious why, in this instance, practicality does not beat purity?
> >
> >Because it's practical not to break bugfix releases with new features.
> 
> And because now your code is incompatible with three micro-release versions
> (3.2.0, 3.2.1, and 3.2.2), two of which are bug fix releases.  Which means for
> example, you can't be sure which version of which distro your code will work
> on.

That I do sympathize with.

> Doesn't anybody else remember the True/False debacle in 2.2.1?

I do.  It was slightly different than this because the feature was added
twice, once in 2.2.1 with direct aliases to 0 and 1, which was found to
be lacking, and then later again in 2.3 with explicit types, so it was
sort of an extended-timeframe unpleasantness, and the feature's
minor-dot-introduction was only a contributing factor, IIRC.

But yeah.  A year from now I wouldn't remember which version of 3.2 got
a new feature, and neither would anybody else.  The no-new-features
guidelines are useful in the real world this way, because they represent
a coherent policy, as tempting as it is to just jam it in.

- C