django-enumfield

Provides an enumeration Django model field (using IntegerField) with reusable enums and transition validation.

Installation

Currently, we test Django versions 2.2-4.1 and Python versions 3.7-3.11.

Install django-enumfield in your Python environment:

$ pip install django-enumfield

Upgrading from django-enumfield 1.x?See the migration guide

For use with Django versions prior to 1.8 use version 1.2.1

For use with Django versions prior to 1.11 use version 1.5

Usage

Create an Enum-class and pass it as first argument to the Django model EnumField.

fromdjango.dbimportmodelsfromdjango_enumfieldimportenumclassBeerStyle(enum.Enum):
LAGER=0STOUT=1WEISSBIER=2classBeer(models.Model):
style=enum.EnumField(BeerStyle, default=BeerStyle.LAGER)
# Use .get to get enum values from either name or intsprint(BeerStyle.get("LAGER")) # <BeerStyle.LAGER: 0>print(BeerStyle.get(1)) # <BeerStyle.STOUT: 1>print(BeerStyle.get(BeerStyle.WEISSBIER)) # <BeerStyle.WEISSBIER: 2># It's also possible to use the normal enum way to get the valueprint(BeerStyle(1)) # <BeerStyle.STOUT: 1>print(BeerStyle["LAGER"]) # <BeerStyle.LAGER: 0># The enum value has easy access to their value and nameprint(BeerStyle.LAGER.value) # 0print(BeerStyle.LAGER.name) # "LAGER"

For more information about Python 3 enums (which our Enum inherits, IntEnum to be specific) checkout the docs.

Setting the default value

You can also set default value on your enum class using __default__ attribute

fromdjango.dbimportmodelsfromdjango_enumfieldimportenumclassBeerStyle(enum.Enum):
LAGER=0STOUT=1WEISSBIER=2__default__=LAGERclassBeerStyleNoDefault(enum.Enum):
LAGER=0classBeer(models.Model):
style_default_lager=enum.EnumField(BeerStyle)
style_default_stout=enum.EnumField(BeerStyle, default=BeerStyle.STOUT)
style_default_null=enum.EnumField(BeerStyleNoDefault, null=True, blank=True)
# When you set __default__ attribute, you can access default value via# `.default()` method of your enum classassertBeerStyle.default() ==BeerStyle.LAGERbeer=Beer.objects.create()
assertbeer.style_default_larger==BeerStyle.LAGERassertbeer.style_default_stout==BeerStyle.STOUTassertbeer.style_default_nullisNone

Labels

You can use your own labels for Enum items

fromdjango.utils.translationimportgettext_lazyfromdjango_enumfieldimportenumclassAnimals(enum.Enum):
CAT=1DOG=2SHARK=3__labels__= {
CAT: gettext_lazy("Cat"),
DOG: gettext_lazy("Dog"),
}
print(Animals.CAT.label) # "Cat"print(Animals.SHARK.label) # "SHARK"# There's also classmethods for getting the labelprint(Animals.get_label(2)) # "Dog"print(Animals.get_label("DOG")) # "Dog"

Validate transitions

The Enum-class provides the possibility to use transition validation.

fromdjango.dbimportmodelsfromdjango_enumfieldimportenumfromdjango_enumfield.exceptionsimportInvalidStatusOperationErrorclassPersonStatus(enum.Enum):
ALIVE=1DEAD=2REANIMATED=3__transitions__= {
DEAD: (ALIVE,), # Can go from ALIVE to DEADREANIMATED: (DEAD,) # Can go from DEAD to REANIMATED
}
classPerson(models.Model):
status=enum.EnumField(PersonStatus)
# These transitions state that a PersonStatus can only go to DEAD from ALIVE and to REANIMATED from DEAD.person=Person.objects.create(status=PersonStatus.ALIVE)
try:
person.status=PersonStatus.REANIMATEDexceptInvalidStatusOperationError:
print("Person status can not go from ALIVE to REANIMATED")
else:
# All goodperson.save()

In forms

The Enum-class can also be used without the EnumField. This is very useful in Django form ChoiceFields.

fromdjangoimportformsfromdjango_enumfieldimportenumfromdjango_enumfield.forms.fieldsimportEnumChoiceFieldclassGenderEnum(enum.Enum):
MALE=1FEMALE=2__labels__= {
MALE: "Male",
FEMALE: "Female",
}
classPersonForm(forms.Form):
gender=EnumChoiceField(GenderEnum)

Rendering PersonForm in a template will generate a select-box with "Male" and "Female" as option labels for the gender field.

Local Development Environment

Make sure black and isort is installed in your env with pip install -e .[dev].

Before committing run make format to apply black and isort to all files.