On 06/28/2018 10:52 PM, Steven D'Aprano wrote:
On Thu, 28 Jun 2018 18:33:31 -0700, Ethan Furman wrote:
Perhaps I am using Enum incorrectly, but here is my FederalHoliday Enum.
Note that date(), next_business_day, and year() are all callables. The
AutoEnum parent assigns values from 1 to n for each member. It's at
Stackoverflow [1] if you'd like up- or down-vote it. ;)
It isn't clear to me why FederalHoliday is an Enum, especially as the API
seems extremely baraque.
Huh. I had to look that word up, and I still don't know what you meant exactly, although I suspect it wasn't
complimentary. ;-)
class FederalHoliday(AutoEnum):
NewYear = "First day of the year.", 'absolute', Month.JANUARY, 1
MartinLutherKingJr = "Birth of Civil Rights leader.", \
'relative', Month.JANUARY, Weekday.MONDAY, 3
...
I think I get the idea... the first field is a description, the second
tells us what month the holiday is in (hope you don't have to deal with
movable holidays which can change months...). I'm not quite sure what the
"absolute/relative" flags are (or why they are strings instead of enums).
Possibly they determine whether the next field is treated as an ordinal
(first, second, third...) or numerical (1, 2, 3...) value.
- description
- type (absolute or relative)
- month
- if absolute:
- date
- else:
- week day
- which one
But what isn't clear to me is why these holidays are *enums*. They're
obviously date instances, with a rich API (at least three methods) and an
extremely complex constructor (one with variable numbers of arguments).
They are the list of dates in which US banks are closed for electronic business
(funds transfers and things).
What makes them enums? Under what circumstances would you be comparing
something to MartinLutherKingJr (Day) without caring about a *specific*
Martin Luther King Jr Day?
Enums are also useful when the underlying value is relevant; the usual example is communicating with other languages'
APIs. While those relevant values may have no intrinsic value, why is it a problem if they do?
--
~Ethan~
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