Django : Change data when model become a choice field

Question

I have a form where I ask people's hobbies. It was a Charfield in my form. I transformed this field with multiple CHOICES. For my old datas, I would like to update their values: for example if they had entered: "football", "skiing", it would have to change to 'sport'.

abstract_models.py

class ReferencesProfileBase(models.Model, UsernameNaturalKeyMixin):
HOBBY_CHOICES = 
    ('sport', ('sport')),
    ('music', ('music')),
    ('travel', ('travel')),
    ('other', ('other')),
)
    customer = models.OneToOneField(
        'customers.CustomerProfile',
        verbose_name=_('Customer'),
        related_name='referencesprofile',
        on_delete=models.CASCADE,
    )
    hobby = models.CharField(
        ('Hobby'),
        max_length=250,
        choices=HOBBY_CHOICES,
        blank=True,
        null=True,
    )

what I want on my old data done automatically:

sport = ["skiing", "football"]
if hobby in sport :
   hobby = "sport"
else :
   hobby = "other"
return hobby

but I don't know in which function to write this code

Answer 1

Use a Data migration by running RunPython operation in the migration as stated in the documentation