Number methods

[Nick Maclaren]

I can't find any description of these. Most are obvious, but some
are not. Note that this is from the point of view of IMPLEMENTING
them, not USING them. Specifically:

Does Python use classic division (nb_divide) and inversion (nb_invert)
or are they entirely historical? Note that I can very easily provide
the latter.

Is there any documentation on the coercion function (nb_coerce)? It
seems to have unusual properties.

Thanks for any hints.


Regards,
Nick Maclaren.

[Ziga Seilnacht]

Re: Number methods

Nick Maclaren wrote:

I can't find any description of these. Most are obvious, but some
are not. Note that this is from the point of view of IMPLEMENTING
them, not USING them. Specifically:

The Python equivalents of these methods are described in the
reference manual:

http://docs.python.org/ref/numeric-types.html

More details can be founf in various PEPs:

http://www.python.org/dev/peps/

Does Python use classic division (nb_divide) and inversion (nb_invert)
or are they entirely historical? Note that I can very easily provide
the latter.

Python uses classic divison by default. True divison is used only when
the division __future__ directive is in effect. See PEP 238 for
details:

http://www.python.org/dev/peps/pep-0238/

The nb_invert method is used for the implementation of the bitwise
inverse unary operator (~). I don't think that it is deprecated. See:
http://docs.python.org/lib/bitstring-ops.html for details.

Is there any documentation on the coercion function (nb_coerce)? It
seems to have unusual properties.

It is used for old style Python classes and extension types that
don't have Py_TPFLAGS_CHEC KTYPES in their tp_flags. See:

http://docs.python.org/ref/coercion-rules.html

and

http://www.python.org/dev/peps/pep-0208/

for details.

Ziga