from mongoengine import * class Union(Document): name = StringField() logo = ImageField(thumbnail_size=(120,120)) description = StringField() legal_registration_number = StringField() headquarter = StringField() def save(self,*args, **kwargs): super(Union, self).save(*args, **kwargs) from .Group import Group group = Group() group.union = self group.name = 'Root' group.rights = ["*::*::{}}/*".format(self.id)] group.save()