On 30 January 2013 16:26, Antoine Pitrou <solipsis@pitrou.net> wrote:

Le Wed, 30 Jan 2013 15:22:06 +0000,

Michael Foord <fuzzyman@gmail.com> a
écrit :

> On 30 January 2013 07:26, Antoine Pitrou
> <solipsis@pitrou.net> wrote:
>
> > On Wed, 30 Jan 2013 17:58:37 +1300
> > Greg Ewing <greg.ewing@canterbury.ac.nz>
> > wrote:
> > > Guido van Rossum wrote:
> > >
> > > > class color(enum):
> > > > RED = value()
> > > > WHITE = value()
> > > > BLUE = value()
> > >
> > > We could do somewhat better than that:
> > >
> > > class Color(Enum):
> > > RED, WHITE, BLUE = range(3)
> >
>
>
>
> With a Python 3 metaclass that provides default values for *looked up*
> entries you could have this:
>
> class Color(Enum):
> RED, WHITE, BLUE

This relies on tuple evaluation order,

It does if you do them as a tuple.

and would also evaluate any
other symbol looked up from inside the class body

Only if they aren't actually defined.

(which means I
cannot add anything else than enum symbols to the class).

So not true - it is only *undefined* symbols that are added as enum values.

In other words, I'm afraid it would be somewhat fragile ;)

Well, within specific parameters...

Michael

Regards

Antoine.

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