Choices for Choices in Django CharFields

models.py

from .utils import ChoiceEnum

class Car(models.Model):
    # Encapsulation, we meet again.
    class Colors(ChoiceEnum):
        RED = 'red'
        WHITE = 'white'
        BLUE = 'blue'

    color = models.CharField(max_length=5, choices=Colors.choices(), default=Colors.RED)
    # ...

# Querying requires an extra word to type though...
red_cars = Car.objects.filter(color=Car.Colors.RED.value)

utils.py

from enum import Enum
class ChoiceEnum(Enum):
    @classmethod
    def choices(cls):
        return tuple((x.name, x.value) for x in cls)