Django模型中的抽象继承,导致MAX递归深度误差

Question

我正在尝试使用以下代码在Django中实现抽象继承,但它会产生MAX递归深度错误.我试图覆盖模型的save方法.

class BaseModel(models.Model):
    class Meta:
        abstract = True

    def save(self, *args, **kwargs):
        #i'm doing something here

        #i think the problem is in the return statement specifically because of the
        #self.__class__ expression.
        return super(self.__class__, self).save(*args, **kwargs)

class MyModel(BaseModel):
    p = models.CharField(max_length=30)

产生此错误(跟踪结束,它很长):

  File "/home/jultra/ap3w/jultra_01/mysite/testsite/models.py", line 10, in save
    return super(self.__class__, self).save(*args, **kwargs)
  File "/home/jultra/ap3w/jultra_01/mysite/testsite/models.py", line 10, in save
    return super(self.__class__, self).save(*args, **kwargs)
  File "/home/jultra/ap3w/jultra_01/mysite/testsite/models.py", line 10, in save
    return super(self.__class__, self).save(*args, **kwargs)
  File "/home/jultra/ap3w/jultra_01/mysite/testsite/models.py", line 10, in save
    return super(self.__class__, self).save(*args, **kwargs)
RuntimeError: maximum recursion depth exceeded

Answer 1

难道不叫super上self.__class__!在实际课程上调用它:

return super(BaseModel, self).save(*args, **kwargs)

这是因为self.__class__始终引用实例的实际具体类.所以,如果你继承MyModel从BaseModel,当你的save方法BaseModel self.__class__仍然是MyModel.所以它找到了MyModel的超级,它是BaseModel,因此调用BaseModel中的save,它再次找到了MyModel的超级...