(original) (raw)

On Wed, 1 May 2013 13:05:53 -0700
Eli Bendersky <eliben@gmail.com> wrote:
\> On Wed, May 1, 2013 at 11:59 AM, Georg Brandl <g.brandl@gmx.net> wrote:
\>
\> > Am 01.05.2013 20:44, schrieb Antoine Pitrou:
\> > > On Wed, 01 May 2013 10:21:30 -0700
\> > > Ethan Furman <ethan@stoneleaf.us> wrote:
\> > >> We may not want to /completely/ disallow subclassing. �Consider:
\> > >>
\> > >> --> class StrEnum(str, Enum):
\> > >> ... � �'''string enums for Business Basic variable names'''
\> > >> ...
\> > >> --> class Vendors(StrEnum):
\> > >> EnumError: subclassing not allowed
\> > >
\> > > I don't see the point of disallowing subclassing. It sounds like
\> > > a pointless restriction.
\> > >
\> > > However, perhaps the constructor should forbid the returning of a base
\> > > type, e.g.:
\> > >
\> > > class Season(Enum):
\> > > � � spring = 1
\> > >
\> > > class MySeason(Season):
\> > > � � """I look nicer than Season"""
\> > >
\> > > MySeason('spring')
\> > > ...
\> > > ValueError: Season.spring is not a MySeason instance
\> > >
\> > > (what this means is perhaps the subclassing of non-empty enum classes
\> > > should be forbidden)
\> >
\> > That's exactly what's implemented in the ref435 code at the moment.
\> >
\> >
\> It can't be because \_\_call\_\_ is by-value lookup, not by-name lookup.

Ok, I've mixed up the example. But, still, since Season(1) should
return the Season.spring singleton, I don't see any reasonable thing
for MySeason(1) to return. Hence the request to raise an exception.