data migrations for django

migration.py

# -*- coding: utf-8 -*-
# Generated by Django 1.10.6 on 2017-04-04 08:08
from __future__ import unicode_literals

from django.db import migrations
# python manage.py dumpdata > dump.json 
def load_fixture(apps, schema_editor):
    from django.core.serializers import base, python
    from django.core.management import call_command
    # Save the old _get_model() function
    old_get_model = python._get_model
    # Define new _get_model() function here, which utilizes the apps argument to
    # get the historical version of a model. This piece of code is directly stolen
    # from django.core.serializers.python._get_model, unchanged.
    def _get_model(model_identifier):
        try:
            return apps.get_model(model_identifier)
        except (LookupError, TypeError):
            raise base.DeserializationError("Invalid model identifier: '%s'" % model_identifier)

    # Replace the _get_model() function on the module, so loaddata can utilize it.
    python._get_model = _get_model
    # Call loaddata command
    call_command('loaddata', 'dump.json', app_label='pay')
    # Restore old _get_model() function
    python._get_model = old_get_model


class Migration(migrations.Migration):

    dependencies = [
        ('lpmk', '0010_auto_20170407_1033'),
        ('sessions', '0001_initial'),
    ]

    operations = [
        migrations.RunPython(load_fixture)
    ]