[Python-ideas] Enums

[Nick Coghlan]

On Sat, Jul 30, 2011 at 1:09 AM, Guido van Rossum <guido at python.org> wrote:
> That's assuming the data export format doesn't support enums.
>
> I would fine enums whose str() is just an int pretty annoying. Note
> that str(True) == repr(True) == 'True' and that's how I'd like it to
> be for enums in general. If you want the int value, use int(e). If you
> want the class name, use e.__class__.__name__ (maybe e.__class__ is
> what you're after anyway). My observation is that most enums have
> sufficiently unique names that during a debugging session the class is
> not a big mystery; it's the mapping from value to name that's hard to
> memorize. As a compromise, I could live with str(e) == 'red' and
> repr(e) == 'Color.red'. But I don't think I could stomach str(e) == 1.

For enums that define new values which are not equivalent to the
underlying values, I agree with you, but my concept for named values
is to allow them to be almost entirely a drop-in replacement for the
values they replace. For that more general use case, changing the
result of str() would be problematic, since str() is often used to
create command line APIs and other things. With a named value
'nv.__name__' would give the name, while 'str(nv)' would give the
original unadorned string representation.

Cheers,
Nick.

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