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。我正在尝试覆盖模型的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

不在super上拨打self.__class__！在实际课程上调用它：

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

这是因为self.__class__总是引用实例的实际具体类。因此，如果您从MyModel继承BaseModel，那么当您save BaseModel中的self.__class__方法仍然是MyModel时。所以它找到MyModel的超级，它是BaseModel，所以在BaseModel中调用save，它再次找到了MyModel的超级...

Django模型中的抽象继承，导致MAX递归深度误差

1 个答案: