Re: Python 3.1 support

I wrote:
> On tor, 2009-11-12 at 16:06 -0500, Tom Lane wrote:
> > There was considerable debate earlier about whether we wanted to treat
> > Python 3 as a separate PL so it could be available in parallel with
> > plpython 2, because of the user-level coding incompatibilities. It
> > looks like this patch simply ignores that problem. What is going to
> > happen to plpython functions that depend on 2.x behavior?
>
> I have a proposal for how to handle this, and a prototype patch
> attached. This follows essentially what the CPython distribution itself
> does, which will make this tolerably easy to follow for users.
>
> We install plpython as plpython2.so or plpython3.so, depending on the
> version used to build it. Then, plpython.so is a symlink to
> plpython2.so.

So here is the potentially final patch for this, including the original
port of plpython.c itself, build system adjustments, and documentation.