Enum for use with Django ChoiceField

django_choices_enum.py

from enum import Enum, EnumMeta, IntEnum, unique


def not_callable_in_template(cls):
    """Disable the callable behavior of Enum in django templates"""
    cls.do_not_call_in_templates = True
    return cls


class ChoiceEnumMeta(EnumMeta):
    def __iter__(cls):
        return ((str(enum_member), enum_member.value)
                for enum_member in super().__iter__())


@not_callable_in_template
class ChoiceEnum(Enum, metaclass=ChoiceEnumMeta):
    def __str__(self):
        return self.name

    def __eq__(self, other):
        return str(self) == str(other)

    @property
    def label(self):
        return self.value


class IntChoiceEnumMeta(EnumMeta):
    def __iter__(cls):
        return ((enum_member.value, enum_member.label) for enum_member in super().__iter__())


@not_callable_in_template
@unique
class IntChoiceEnum(IntEnum, metaclass=IntChoiceEnumMeta):
    """Attributes:
        __choices_label_map__ should return Dict[EnumMember, Label] where:
            EnumMember - ColorEnum.RED
            Label - str or lazy(str)
    """
    __choices_label_map__ = {}

    @property
    def label(self):
        return self.__choices_label_map__.get(self, '')

django_choices_enum_example.md

Usage of ChoiceEnum

Enum definition

from django.utils.translation import ugettext_lazy as _

from django_choices_enum.enums import ChoiceEnum


class ColorEnum(ChoiceEnum):
    RED = _('Red')
    BLUE = _('Blue')
    GREEN = _('Green')

In models:

from django.db import models
from django.utils.translation import ugettext_lazy as _
from .enums import ColorEnum

class ColorPalette(models.Model):
    color = models.CharField(_('Color'), max_length=30, choices=ColorEnum)

Querying:

ColorPalette.objects.filter(color=ColorEnum.RED)

In templates:

View:

def my_page(request):
    context = {
        'ColorEnum': ColorEnum,
        'color_palette': ColorPalette.objects.filter(color=ColorEnum.BLUE).first(),
    }

    return render(request, 'my_app/index.html', context)

Template:

<p>The color is {% if color_palette.color == ColorEnum.BLUE %}blue{% else %}not blue{% endif %}</p>

Will result in:

<p>The color is blue</p>

Comparing:

In [1]: ColorEnum.GREEN == 'GREEN'
Out[1]: True

Getting the label:

In [1]: ColorEnum.RED.label
Out[1]: 'Red'

---

Usage of IntChoiceEnum

Enum definition

from django.utils.translation import ugettext_lazy as _

from django_choices_enum.enums import IntChoiceEnum


class ShakeEnum(IntChoiceEnum):
    CHOCO = 1
    VANILLA = 2
    MINT = 3

    __choices_label_map__ = {
        CHOCO: _('Chocolatey'),
        VANILLA: _('Vanilla'),
        MINT: _('Minty'),
    }

In models:

from django.db import models
from django.utils.translation import ugettext_lazy as _
from .enums import ShakeEnum

class Smoothie(models.Model):
    shake = models.SmallIntegerField(_('Shake'), choices=ShakeEnum)

Querying:

Smoothie.objects.filter(shake=ShakeEnum.VANILLA)

In templates:

View:

def my_page(request):
    context = {
        'ShakeEnum': ShakeEnum,
        'smoothie': Smoothie.objects.filter(shake=ShakeEnum.MINT).first(),
    }

    return render(request, 'my_app/index.html', context)

Template:

<p>Your shake contains {% if smoothie.shake == ShakeEnum.MINT %}fresh mint{% else %}something not minty{% endif %}</p>

Will result in:

<p>Your shake contains fresh mint</p>

Comparing:

In [1]: ShakeEnum.MINT == 3
Out[1]: True

Getting the label:

In [1]: ShakeEnum.MINT.label
Out[1]: 'Minty'