[Python-Dev] peps: Update PEP 399 to include comments from python-dev.

[Raymond Hettinger]

On Apr 13, 2011, at 4:52 AM, Antoine Pitrou wrote:

> On Wed, 13 Apr 2011 06:28:58 +0200
> Stefan Behnel <stefan_ml at behnel.de> wrote:
>> 
>> However, I think we are really discussing a theoretical issue here. All the 
>> PEP is trying to achieve is to raise the bar for C code in the stdlib, for 
>> exactly the reason that it can easily introduce subtle semantic differences 
>> in comparison to generic Python code.
> 
> True. But then we're much better without a formal requirement that
> some people will start trying to require because they don't understand
> that its metric is pointless.

I concur.

For most part, anyone converting from C-to-Python or Python-to-C
is already doing their best to make the two as similar as they can.
The PEP falls short because its coverage metric conflates 
the published API with its implementation details.  
The PEP seems confused about the role of white box testing
versus black box testing.
Nor does the PEP provide useful guidance to anyone working 
on a  non-trivial conversion such as decimal, OrderedDict, or threading.

If the underlying theme is "nothing written in C is good for PyPy",
perhaps the PEP should address whether we want any new
C modules at all.  That would be better than setting a formal
requirement that doesn't address any of the realities of building
two versions of a module and keeping them in sync.


Raymond