def create_head(self):
    'Create head for this trial'
    session = relational.make_session()
    session.query(Head.m).filter((Head.m.script == self.script)).delete()
    session.add(Head.m(trial_id=self.id, script=self.script))
    session.commit()
Create head for this trial
def create_head(self):
    
    session = relational.make_session()
    session.query(Head.m).filter((Head.m.script == self.script)).delete()
    session.add(Head.m(trial_id=self.id, script=self.script))
    session.commit()