#36930: Using a custom ModelChoices (not IntegerChoices or TextChoices) member 
as
the default value of a model field doesn't select the default value in
form's select
-------------------------------------+-------------------------------------
     Reporter:  Antoine Humbert      |                     Type:  Bug
       Status:  new                  |                Component:  Database
                                     |  layer (models, ORM)
      Version:  6.0                  |                 Severity:  Normal
     Keywords:                       |             Triage Stage:
                                     |  Unreviewed
    Has patch:  0                    |      Needs documentation:  0
  Needs tests:  0                    |  Patch needs improvement:  0
Easy pickings:  0                    |                    UI/UX:  0
-------------------------------------+-------------------------------------
 This was triggered in the following forum post:
 https://forum.djangoproject.com/t/default-for-choices-field-isnt-default-
 in-admin-form/44189

 As per the documentation and the **date** / **DateField** example (see
 https://docs.djangoproject.com/en/6.0/ref/models/fields/#enumeration-
 types), defining choices for a data type other than **int** or **str**
 (e.g. float) should be :

 {{{
 class FactorChoices(float, models.Choices):
     HALF = 0.5
     SINGLE = 1
     DOUBLE = 2
 }}}

 then, setting a default value for a field should use one of the
 enumeration's member (as per the example from documentation:
 `default=YearInSchool.FRESHMAN`). E.g.:

 {{{
 class SomeModel(models.Model):
     factor = models.FloatField(choices=FactorChoices,
 default=FactorChoices.SINGLE)
 }}}


 When using such definitions, the default value is not selected by default
 in forms created for such model. This is bescause the `str()` of the
 default value returns the string representation provided by `enum.Enum`
 instead of the string representation from `float`.

 I believe this is a regression in
 
https://github.com/antoinehumbert/django/commit/fe19b33e2f76045617067dd5123041ae4d3a91ee
 where the `django.db.models.Choices.__str__` (which specifically called
 `str(self.value)`) method was removed to the profit of making
 `IntegerChoices` and `TextChoices` inherit from `enum.ReprEnum`).
 Unfortunaltly, this dropped the initial `Choices.__str__` behaviour for
 all other subclasses of `Choices`.

 I think the fix is as simple as making `Choices` inherit from
 `enum.ReprEnum` instead of `enum.Enum`.

 I'm working on a PR.
-- 
Ticket URL: <https://code.djangoproject.com/ticket/36930>
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