[Python-Dev] PEP 435 -- Adding an Enum type to the Python standard library

Ethan Furman ethan at stoneleaf.us
Fri Apr 26 07:21:15 CEST 2013


On 04/25/2013 08:14 PM, Greg wrote:
> On 26/04/2013 1:28 p.m., Ethan Furman wrote:
>> Interesting idea, but why does Day(3) have to be disallowed to make it
>> work?
>
> Because it's ambiguous. Which day of the week is number 3? It
> depends on where you start.

Ah.


> I should perhaps point out that the numbers assigned to the
> values initially are just to establish the relative ordering.
> They wouldn't be directly accessible once the values are
> created. To get an integer value corresponding to a Day value,
> you would have to do arithmetic:
>
>     Day.wednesday - Day.sunday --> 3

That would make it very hard to do data storage and retrieval.

--
~Ethan~


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