datamigration.py

 def forwards(self, orm): 
    for a in orm.Author.object.all(): 
        try: 
            a.first_name, a.second_name = a.name.split(" ")
        except:
            a.first_name, a.second_name = a.name, "" 
        c.save() 

 def backwards(self, orm): 
    for a in orm.Author.object.all():
        a.name = ""
        a.save()