[Python-ideas] Is there a reason some of the PyLong_As* functions don't call an object's __int__?

[Nick Coghlan]

On 29 December 2017 at 22:58, Erik Bray <erik.m.bray at gmail.com> wrote:
> On Thu, Dec 28, 2017 at 8:42 PM, Serhiy Storchaka <storchaka at gmail.com> wrote:
>> 28.12.17 12:10, Erik Bray пише:
>>>
>>> There's no index() alternative to int().
>>
>>
>> operator.index()
>
> Okay, and it's broken.

Broken in what way? It has a fairly extensive test suite in
https://github.com/python/cpython/blob/master/Lib/test/test_index.py
(and some additional indirect testing in test_slice.py, which assumes
that it works as advertised).

>  That doesn't change my other point that some
> functions that could previously take non-int arguments can no
> longer--if we agree on that at least then I can set about making a bug
> report and fixing it.

The size_t, ssize_t and void pointer conversions should only accept
true integers (so either no fallback, or fall back to `__index__`).

The unsigned long and unsigned long long conversions should likely be
consistent with their signed counterparts and allow lossy conversions
via `__int__`.

I'm less sure about the conversion to double, but allowing that to be
used on float objects without reporting a type error seems like a bug
magnet to me.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia