# django-enumfield
Provides an enumeration Django model field (using `IntegerField`) with reusable enums and transition validation.
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[](https://pypi.python.org/pypi/django-enumfield)
[](https://pypi.python.org/pypi/django-enumfield)
[](https://pypi.python.org/pypi/django-enumfield)
[](https://pypi.python.org/pypi/django-enumfield)

Installation
------------
Currently, [we test](https://github.com/5monkeys/django-enumfield/actions) Django versions 2.2-4.1 and Python versions 3.7-3.11.
Install `django-enumfield` in your Python environment:
```sh
$ pip install django-enumfield
```
**Upgrading from django-enumfield 1.x?** [See the migration guide](docs/migrate-to-20.md)
For use with Django versions prior to 1.8 use version
[`1.2.1`](https://github.com/5monkeys/django-enumfield/tree/1.2.1)
For use with Django versions prior to 1.11 use version
[`1.5`](https://github.com/5monkeys/django-enumfield/tree/1.5)
Usage
-----
Create an `Enum`-class and pass it as first argument to the Django model `EnumField`.
```python
from django.db import models
from django_enumfield import enum
class BeerStyle(enum.Enum):
LAGER = 0
STOUT = 1
WEISSBIER = 2
class Beer(models.Model):
style = enum.EnumField(BeerStyle, default=BeerStyle.LAGER)
# Use .get to get enum values from either name or ints
print(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 value
print(BeerStyle(1)) # <BeerStyle.STOUT: 1>
print(BeerStyle["LAGER"]) # <BeerStyle.LAGER: 0>
# The enum value has easy access to their value and name
print(BeerStyle.LAGER.value) # 0
print(BeerStyle.LAGER.name) # "LAGER"
```
For more information about Python 3 enums
(which our `Enum` inherits, `IntEnum` to be specific)
checkout the [docs](https://docs.python.org/3/library/enum.html).
### Setting the default value
You can also set default value on your enum class using `__default__`
attribute
```python
from django.db import models
from django_enumfield import enum
class BeerStyle(enum.Enum):
LAGER = 0
STOUT = 1
WEISSBIER = 2
__default__ = LAGER
class BeerStyleNoDefault(enum.Enum):
LAGER = 0
class Beer(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 class
assert BeerStyle.default() == BeerStyle.LAGER
beer = Beer.objects.create()
assert beer.style_default_larger == BeerStyle.LAGER
assert beer.style_default_stout == BeerStyle.STOUT
assert beer.style_default_null is None
```
### Labels
You can use your own labels for `Enum` items
```python
from django.utils.translation import gettext_lazy
from django_enumfield import enum
class Animals(enum.Enum):
CAT = 1
DOG = 2
SHARK = 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 label
print(Animals.get_label(2)) # "Dog"
print(Animals.get_label("DOG")) # "Dog"
```
### Validate transitions
The `Enum`-class provides the possibility to use transition validation.
```python
from django.db import models
from django_enumfield import enum
from django_enumfield.exceptions import InvalidStatusOperationError
class PersonStatus(enum.Enum):
ALIVE = 1
DEAD = 2
REANIMATED = 3
__transitions__ = {
DEAD: (ALIVE,), # Can go from ALIVE to DEAD
REANIMATED: (DEAD,) # Can go from DEAD to REANIMATED
}
class Person(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.REANIMATED
except InvalidStatusOperationError:
print("Person status can not go from ALIVE to REANIMATED")
else:
# All good
person.save()
```
### In forms
The `Enum`-class can also be used without the `EnumField`. This is very useful in Django form `ChoiceField`s.
```python
from django import forms
from django_enumfield import enum
from django_enumfield.forms.fields import EnumChoiceField
class GenderEnum(enum.Enum):
MALE = 1
FEMALE = 2
__labels__ = {
MALE: "Male",
FEMALE: "Female",
}
class PersonForm(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.