[Python-Dev] Deprecating C APIs (Use of PyArg_NoArgs())

[Guido van Rossum]

> > > -1 on removing PyArg_NoArgs() ... this API is still in very active
> > > use in third party extensions.
> > 
> > Would it be OK if it issued a warning?
> 
> Hmm, people would start screaming, I guess -- this API is used
> far more than e.g. the regex/regsub module combo. A one-time-per-
> module warning would probably be OK though.

That's what I wanted, but now that you mention it I'm not sure if the
warning module can currrently detect from which module a particular C
API is called -- it'll probably put the blame on a particular line in
the user's code, and then repeat the warning for each *different* line
of user code.

> I seriously think that we should install a set of common
> third party extensions somewhere to that we can easily
> check usage of the APIs in the outside world, e.g. take
> the packages Aahz collected recently and unzip them to
> some directory on python.org. A grep would then quickly
> produce proof of "common" usage.

+1

> > > I'd suggest to have a PEP which documents all C API changes
> > > or deprecations together with a short decsription of how to
> > > update old code.
> > 
> > It shouldn't be a PEP (that's a *proposal*).  It should be part of
> > the C API docs, possibly an appendix.
> 
> I was thinking of an informational PEP -- mostly because PEPs
> are easily accessible and also simple to write (LaTeX is not
> everybody's friend ;-).

Yeah, that's fine.  Let whoever writes it decide on the format. :-)

> True, but there are other instances where this was a problem
> in the past, e.g. 
> 
> #if PY_VERSION_HEX < 0x01060000
> 
> #if !defined(PyObject_DEL)
> # define PyObject_DEL(x) free(x)
> # define PyObject_Del(x) free(x)
> #endif
> 
> #endif

Why the PY_VERSION_HEX guard?  Isn't the !defined() guard enough?

--Guido van Rossum (home page: http://www.python.org/~guido/)