def forwards(self, orm):
        for repo in orm.Repository.objects.all():
            username = '' if repo.user is None else slugify(repo.user.username)
            repo.slug = '/'.join([i for i in [username, slugify(repo.name)] if i])
            repo.save()
Write your forwards methods here.
dataset/ETHPy150Open repocracy/repocracy/repocracy/repo/migrations/0004_populate_slug.py/Migration.forwards