On Thu, Feb 19, 2009 at 1:57 PM, Jean-Paul Calderone
<report@bugs.python.org> wrote:
>
> Jean-Paul Calderone <exarkun@divmod.com> added the comment:
>
>> Oh, and "what to do of the now unused pure Python implementations in
> io.py"?  Easiest would be to dump them, as they will probably get
> hopelessly out of sync, but perhaps there's some genuine
> portability/educational advantage to keep them?
>
> The test suite should be run against both implementations.  That way
> tested behavior will always be the same for both.  And all of its
> behavior is tested, right? ;)
>
> The value in the Python implementation is manifold.  For example:
>
>  * It eases testing of new features/techniques.  Rather than going
> straight to the C version when someone has an idea for a feature, it can
> be implemented and tried out in Python.  If it's cool, then the extra
> effort of porting to C can be undertaken.
>  * It helps other Python implementations immensely.  PyPy, IronPython,
> and Jython are all going to have to provide this library eventually (one
> supposes).  Forcing them each to re-implement it will mean it will be
> that much longer before they support it.

We don't maintain any other features in two languages for those
purposes. IMO, it will just be more of a burden to fix bugs in two
different places as compared to the advantages you mention.