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

[James Y Knight]

On Apr 6, 2011, at 10:08 AM, Nick Coghlan wrote:

> On Wed, Apr 6, 2011 at 5:57 AM, Raymond Hettinger
> <raymond.hettinger at gmail.com> wrote:
>> [Brett]
>>> This PEP requires that in these instances that both
>>> the Python and C code must be semantically identical
>> 
>> Are you talking about the guaranteed semantics
>> promised by the docs or are you talking about
>> every possible implementation detail?
>> 
>> ISTM that even with pure python code, we get problems
>> with people relying on implementation specific details.
> 
> Indeed.
> 
> Argument handling is certainly a tricky one - getting positional only
> arguments requires a bit of a hack in pure Python code (accepting
> *args and unpacking the arguments manually), but it comes reasonably
> naturally when parsing arguments directly using the C API.

Perhaps the argument handling for C functions ought to be enhanced to work like python's argument handling, instead of trying to hack it the other way around?

James