Unused import on some auto generated migrations

[Hugo Tácito]

Some auto generated migrations don't use django.db.models. Especially those that only change the Meta class. It would be nice to change the django.db.migrations.writer.MIGRATION_TEMPLATE to only add the from django.db import models if its really needed.

Example of auto generated migration with unused import:

# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.db import models, migrations


class Migration(migrations.Migration):

    dependencies = [
        ('city', '0003_auto_20150305_0928'),
    ]

    operations = [
        migrations.AlterModelOptions(
            name='city',
            options={'verbose_name': 'City', 'verbose_name_plural': 'Cities'},
        ),
    ]

[Markus Holtermann]

I think models is a convenience import and should stay around.

[Chris Luc]

I think having models in a migration that doesn't use the import might spark confusion for why it's being imported in the first place. I think it makes the migrations cleaner by not having unused imports. I don't see many situations where someone would manually need the models import. But, in the rare occasion that they do need it, manually adding it is not that bad. @MarkusH

[Hugo Tácito]

Personally I'm having problems when I do automated code analysis with pylint. I know this can be solved just ignoring the migrations folder but it would be nice if django only do this import when necessary on auto generated migrations.

[Tim Graham <timograham@…>]

In a7bc00e1:

Fixed #24514 -- Made migration writer omit models import if it's unused.