更改状态odoo 11之后创建复制模型

Question

我想在状态更改完成或接受后创建副本

    class Studentclass(models.Model):
    _name = 'student.class'

    state = fields.Selection([ ('accepted', 'Accepted'), ('done', 'Success'),
                              ('not_pass', 'Not Pass'), ('absent', 'Absent ')], string='State', default='no_date')
    type = fields.Selection([('exp', 'Exp'), ('main', 'Main')], string='Type')
 ...



    @api.multi
    def copy(self, default=None):
        default = dict(default or {})
        default.update({'type': 'main'})
        return super(Studentclass, self).copy(default)