[Python-ideas] Enums

[Barry Warsaw]

On Jul 28, 2011, at 10:30 AM, Nick Coghlan wrote:

>I did see that, but I don't see a straighforward way to do it without
>locking the enum implementation into being *specifically* for
>integers.

Which is fine by me, FWIW.

>>>1. I find the "enum" concept too limiting. NamedValue (as a mixin
>>>class) is a better building block since it separates the naming aspect
>>>from the "group of values" aspect implied by enum.
>>
>> I think that's all fine, but it's getting far from *my* simple concept of
>> enumerated values.  Go for it though. :)
>
>How is something that does *less* more complicated?

Again, looking at how I've used them extensively over the last several years,
I would much rather write

    class Colors(Enum):
        red = 1
        green = 2
        blue = 3

than

    red = NamedValue('red', 1)
    green = NamedValue('green', 2)
    blue = NamedValue('blue', 3)

To me, the duplication is jarring and error prone.

>But the *necessity* of grouping creates a lot of boilerplate and
>prevents TOOWTDI.

I have no problem if folks want to add named values to the stdlib.  I use
namedtuple on occasion, and I wouldn't mind having named values in my arsenal,
but I'm fairly certain I wouldn't use named values in the places I use Enum
currently.  The grouping does provide benefits such as disallowing duplicates,
providing for an inheritance mechanism, and making them easier to pickle and
store in (and load from) a database.

I didn't original think of using enums as a replacement for module level
constants, so I think we're just talking about different use cases.

-Barry
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