How to remove default value function in Django

Question

In the commentary on the answer to this question, I asked how to remove a field with a default value. To summarize, example code:

def get_deadline():
    return datetime.today() + timedelta(days=20)

class Bill(models.Model):
    name = models.CharField(max_length=50)
    customer = models.ForeignKey(User, related_name='bills')
    date = models.DateField(default=datetime.today)
    deadline = models.DateField(default=get_deadline)

and my question to the code:

How to delete a field deadlineagain and also delete a get_deadlinefunction? I deleted the field with the function for the default value, but now Django crashes at startup after deleting the function. I could manually change the migration, which would be normal in this case, but what if you just changed the default function and wanted to delete the old function?

I ended up deleting the default part related to it, but how to remove it?

The only way I can think of is to deflate migrations so that the migration with the function disappears, but this is not always an option.

Answer 1

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Answer 2

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Answer 3

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Answer 4

My direct answer will delete sqlite3.dband delete all migrations except __init__.pyin the migration folder in each application.

Then run python again

$manage.py makemigrations
$python manage.py migrate