django model field choices

what is it?

when creating a model in django a field can be constricted to only contain certain values, adding a choices parameter

from the django documentation:

from django.db import models
 
YEAR_IN_SCHOOL_CHOICES = [
    ("FR", "Freshman"),
    ("SO", "Sophomore"),
    ("JR", "Junior"),
    ("SR", "Senior"),
    ("GR", "Graduate"),
]
 
class Student(models.Model):
	name = models.CharField()
	year = models.Charfield(max_length=2, choices=YEAR_IN_SCHOOL_CHOICES)

enumeration types

these choices are similar to the standard python enum library, but with some added django magic

TextChoices

from django.db import models
 
class YearInSchool(models.TextChoices):
    FRESHMAN = "FR", "Freshman"
    SOPHOMORE = "SO", "Sophomore"
    JUNIOR = "JR", "Junior"
    SENIOR = "SR", "Senior"
    GRADUATE = "GR", "Graduate"
 
class Student(models.Model):
    year_in_school = models.CharField(
        max_length=2,
        choices=YearInSchool.choices,
        default=YearInSchool.FRESHMAN,
    )

• .label will display the human readable name
  • YearInSchool.FRESHMAN.label will return Freshman
  • YearInSchool("FR").label will also return Freshman

IntegerChoices

enumeration with integers instead of text

class Suit(models.IntegerChoices):
	DIAMOND = 1
	SPADE = 2
	HEART = 3
	CLUB = 4
 
class Card(models.Model):
    suit = models.IntegerField(choices=Suit)

can also add labels if required

class Suit(models.IntegerChoices):
	DIAMOND = 1, "Diamond Card"
	SPADE = 2, "Spade Card"
	HEART = 3, "Heart Card"
	CLUB = 4, "Club Card"