[Python-ideas] PEP for enum library type?

[Tim Delaney]

On 14 February 2013 05:19, Barry Warsaw <barry at python.org> wrote:

> On Feb 13, 2013, at 08:19 AM, Tim Delaney wrote:
>
> >I'm of the opinion that the most fundamental property of an enum is that
> it
> >can generate its values automatically. Everything else is a nice-to-have,
> >but without that property it's not much use as an enum.
>
> See, I don't care about that much because I define an enum once, but I
> *use*
> it hundreds of times.  Thus a little more verbosity/explicitness at
> definition
> time is a one-time cost, and a very low one at that.  It might not seems
> that
> way when you're writing them in so many mailing list replies though ;).
>

My main concern regarding this is ensuring that:

1. Values don't get repeated.

2. Values don't get skipped (unless explicitly skipped);

#1 obviously is the most important property, but in practice I find #2 to
be very important as well. Whilst it's more verbose, the ... syntax isn't
bad, and I've added support to it to my enum to play with. Currently my
enum implementation includes the kitchen sink, but I'm looking to do some
renovations soon.


> In real code, having a really good str and repr, along with good semantics
> makes them much more useful for debugging, and very pleasant to use.
>

Absolutely. But it's not just that either. If you can convert from the
string name to the enum, it makes the enum suitable as a transport
mechanism. Each end can have different values for the enum in practice so
long as the names don't change - it can make things much more robust across
versions.

Tim Delaney
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