Django retrieve key of group ChoiceField - django

Question

retrieve key of group ChoiceField
MEDIA_CHOICES = (
('Audio', (
('vinyl', 'Vinyl'),
('cd', 'CD'),
)
),
('Video', (
('vhs', 'VHS Tape'),
('dvd', 'DVD'),
)
),
('unknown', 'Unknown'),
)
class ressource(models.Model):
....
media = models.CharField(max_length=50, choices=MEDIA_CHOICES)
in field media i have vinyl or cd or vhs or dvd...but how retrieve audio,video, unknown ?

Answer 1

You should prove us more details. First of all choices should be iterable object (tuple for example as it's in your case), but your tuple is very complicated in your case (Django can not process this). You should pass something like this as a choices.
choices example (This is good tuple code)
CHOICES = (
('key', 'value') # key will be inserted in database (and validation purposes), and value is just for representation purposes.
)
LANGUAGES = (
('python', 'Python'),
('js', 'JS'),
('ruby', 'Ruby'),
)
Imagine that, you are trying to retrieving object from database.
class ressource(models.Model):
''' This is your model '''
media = models.CharField(max_length=50, choices=MEDIA_CHOICES)
res = ressource.objects.get(pk=1) # retrieve data from database.
print(res.media) # returns string object. you will read actual value of media field
''' But if you want to read all available choices on this field, Django provide as _meta api. You can use it very nice way '''
res = ressource.objects.get(pk=1)
fields = res._meta.fields # This will return tuple-like object.
for field in fields:
if field.name == 'media':
# you want to find "media" field
print(field.choices) # This will return all available choices on your media field
Hope, it helps you. Good luck.