text: from __future__ import unicode_literals
  
  from django.db import migrations, models
  
  
  def move_data(apps, schema_editor):
      Product = apps.get_model('product', 'Product')
      ProductClass = apps.get_model('product', 'ProductClass')
  
      for product in Product.objects.all():
          attributes = product.attributes.all()
          product_class = ProductClass.objects.all()
          for attribute in attributes:
              product_class = product_class.filter(
                  variant_attributes__in=[attribute])
          product_class = product_class.first()
          if product_class is None:
              product_class = ProductClass.objects.create(
                  name='Unnamed product type',
                  has_variants=True)
              product_class.variant_attributes = attributes
              product_class.save()
          product.product_class = product_class
          product.save()
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('product', '0019_auto_20161212_0230'),
      ]
  
      operations = [
          migrations.RunPython(move_data),
      ]
  