[Python-Dev] PEP 399: Pure Python/C Accelerator Module Compatibiilty Requirements

[Antoine Pitrou]

On Tue, 19 Apr 2011 10:37:41 -0400
"R. David Murray" <rdmurray at bitdance.com> wrote:

> On Tue, 19 Apr 2011 07:06:09 +0200, Stefan Behnel <stefan_ml at behnel.de> wrote:
> > That's what makes the PEP feel so unfair to CPython developers, because 
> > they are the ones who carry most of the burden of maintaining the stdlib in 
> > the first place, and who will most likely continue to carry it, because 
> > other implementations will continue to be occupied with their own core 
> > development for another while or two. It is nice to read that other 
> > implementations are contributing back patches that simplify their own reuse 
> > of the stdlib code. However, that does not yet make them equal contributors 
> > to the development and the maintenance of the stdlib, and is of very little 
> > worth to the CPython project. It often even runs counter to the interest of 
> > CPython itself.
> 
> So, the PEP makes the burden worse in that it requires that someone who
> works on a module with a C accelerator must make sure that any existing
> Python version and the C version stay in sync, and that *anyone* who wants
> to introduce a new module into the stdlib must make sure it has a Python
> version if that is practical.  IMO both of these are policies that make
> sense for CPython even aside from the existence of other implementations:
> Python is easier to read and understand, so where practical we should
> provide a Python version of any module in the stdlib, for the benefit
> of CPython users.
> 
> It doesn't sound like a great burden to me, but I'm not really qualified
> to judge, since I don't generally work on C code.

I think it's ok. Our experience on the io module proves, I think,
that's it's indeed useful to have a pure Python (pseudocode-like)
implementation.

Regards

Antoine.