Opened 4 years ago

Last modified 7 months ago

#31262 closed New feature

Support dictionaries in Field.choices for named groups. — at Version 1

Reported by: Tom Forbes Owned by: nobody
Component: Database layer (models, ORM) Version: dev
Severity: Normal Keywords:
Cc: Adam Johnson Triage Stage: Ready for checkin
Has patch: yes Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by Mariusz Felisiak)

The Django documentation gives this example for creating named groups of choices:

MEDIA_CHOICES = [
    ('Audio', (
            ('vinyl', 'Vinyl'),
            ('cd', 'CD'),
        )
    ),
    ('Video', (
            ('vhs', 'VHS Tape'),
            ('dvd', 'DVD'),
        )
    ),
    ('unknown', 'Unknown'),
]

With Python 3.7 (and implicitly in CPython 3.6) dictionaries are ordered, meaning this syntax could be replaced by the cleaner and easier to parse:

{
    "Audio": (
         ('vinyl', 'Vinyl'),
         ('cd', 'CD'),
    ),
    "Video": (
        ('vhs', 'VHS Tape'),
        ('dvd', 'DVD'),
    ),
   "unknown": "Unknown"
}

Once 3.7 is the lowest supported version we should document that this is supported, and ensure that it works correctly.

Change History (1)

comment:1 by Mariusz Felisiak, 4 years ago

Component: Forms → Database layer (models, ORM)
Description: modified (diff)
Summary: Document and explicitly support dictionaries being passed to field choices → Support dictionaries in Field.choices for named groups.
Triage Stage: Unreviewed → Accepted
Version: → master

Agreed, we can officially add this even in Django 3.1, because we've already made a decision to assume that dictionaries preserve ordering (see #30159 and ​a short discussion).

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