Slugify all the country.printable_name and put them in slug field

slugify_countries.py

    def forwards(self, orm):
        """
        Slugify all the country.printable_name and put them in slug field
        """
        from django.template.defaultfilters import slugify
        for country in orm.Country.objects.all():
            country.slug = slugify(country.printable_name)
            countey.save()


    def backwards(self, orm):
        db.delete_column('datacenter_country', 'slug')