How do I do this without class methods ?

[Alex Martelli]

"Jacek Generowicz" <jmg at ecs.soton.ac.uk> wrote in message
news:g0itjjrb6z.fsf at scumbag.ecs.soton.ac.uk...
    [snip]
> OK, I've found an interesting solution to the problem: Alex'
> static-methods recipe . . . but it does seem to mess up inheritance
> somewhat, by having to replace self._class__.unit_area with the more
> explicit and specific polygon.unit_area in polygon.set_class_cache.
> Is there a way of improving on this ?

Depends on what you consider an improvement.  You do have to
pass the class-object *somewhere*, either implicitly or explicitly.

>     def set_class_cache ( N ):

You may change this to:
      def set_class_cache(klass, N):

> # The next line had to be changed
> # self.__class__.unit_area = N * math.sin( 2 * math.pi / N )
>         polygon.unit_area = N * math.sin( 2 * math.pi / N )

and therefore this to
          klass.unit_area = whatever

so it becomes perfectly-inheritable,

> def set_parameter_ideal ( klass, N ):
>     klass.set_class_cache( N )

And this call to
      klass.set_class_cache(klass, N)


Alex