How to use Django Field Choices ?

Django Field Choices. According to documentation Field Choices are a sequence consisting itself of iterables of exactly two items (e.g. [(A, B), (A, B) …]) to use as choices for some field. For example, consider a field semester which can have options as { 1, 2, 3, 4, 5, 6 } only. Choices limits the input from the user to the particular values specified in models.py. If choices are given, they’re enforced by model validation and the default form widget will be a select box with these choices instead of the standard text field. Choices can be any sequence object – not necessarily a list or tuple.

The first element in each tuple is the actual value to be set on the model, and the second element is the human-readable name.
For example,

SEMESTER_CHOICES = (
    ("1", "1"),
    ("2", "2"),
    ("3", "3"),
    ("4", "4"),
    ("5", "5"),
    ("6", "6"),
    ("7", "7"),
    ("8", "8"),
)

Let us create a choices field with above semester in our django project named geeksforgeeks.

from django.db import models

# specifying choices

SEMESTER_CHOICES = (
    ("1", "1"),
    ("2", "2"),
    ("3", "3"),
    ("4", "4"),
    ("5", "5"),
    ("6", "6"),
    ("7", "7"),
    ("8", "8"),
)

# declaring a Student Model

class Student(models.Model):
      semester = models.CharField(
        max_length = 20,
        choices = SEMESTER_CHOICES,
        default = '1'
        )

Let us check in admin panel how semester is created.

One can also collect your available choices into named groups that can be used for organizational purposes:

MEDIA_CHOICES = [
    ('Audio', (
            ('vinyl', 'Vinyl'),
            ('cd', 'CD'),
        )
    ),
    ('Video', (
            ('vhs', 'VHS Tape'),
            ('dvd', 'DVD'),
        )
    ),
    ('unknown', 'Unknown'),
]

The first element in each tuple is the name to apply to the group. The second element is an iterable of 2-tuples, with each 2-tuple containing a value and a human-readable name for an option. Grouped options may be combined with ungrouped options within a single list (such as the unknown option in this example).
For each model field that has choices set, Django will add a method to retrieve the human-readable name for the field’s current value. See get_FOO_display() in the database API documentation.