[Python-Dev] python 3.0, tp_compare not used for == test?

[Mark Dickinson]

On Mon, Feb 2, 2009 at 11:38 AM, Nick Coghlan <ncoghlan at gmail.com> wrote:
> That's what the -3 command line switch is for - it sets a boolean flag
> that C code can check to see if it should emit warnings for things that
> are going to break in Python 3.x.

Understood.  My worry was that we'd get a lot of false positives---
i.e., warnings about pieces of Python 2.7 that don't need to change.
But I guess that's okay.

> There's already at least one example
> of its use in typeobject.c (relating to inheritance of the tp_hash
> slot). There are a few other examples about the place (e.g. I believe
> that when -3 is defined the return value of dict.keys and friends is
> changed to a list subclass that warns on certain operations that have
> different semantics in 3.x).

Thanks for the pointers.  I'll take a look and see if I can come up
with a patch.  But I'd like to complete the rest of the cmp removal
stuff first.

Mark