Django覆盖保存

我想在我的模型中覆盖save方法，以创建适当的slug并创建imagefield的副本，只需对其进行一些小的修改。我该怎么处理呢

def save(self, *args, **kwargs):
            super(MyModel, self).save(*args, **kwargs) #to get id

            #slug
            self.slug = '%s-%i' % (self.topic, self.id)

            #create copy of img
            cp_path = dirname(self.image.path)+'/copies_'+basename(self.image.path)
            shutil.copy2(self.image.path, cp_path)

            file = open(cp_path)
            django_file = File(file)
            django_file.name = basename(cp_path) #otherwise path will be duplicated
            self.cp_image = django_file

            super(MyModel, self).save(*args, **kwargs) #to save my new ImageField

            create_watermark(self.cp_image, self.topic, self.text, 500, 45)

---

因为我使用了两次super（MyModel，self）.save（），我得到了self.image文件的副本。正如您所看到的，我对django和python不是很熟悉。如何才能做得更好？

这可能不是最简单的方法，但您可以尝试将

save（）

与。可能看起来像：

class MyModel(Model):
    ## Stuff
    def save(self, *args, **kwargs):
        #create copy of img.  Fixed up to use string formatting.
        cp_path = "%s/copies_%s" % 
            (dirname(self.image.path), basename(self.image.path))
        shutil.copy2(self.image.path, cp_path)
        file = open(cp_path)
        django_file = File(file)
        django_file.name = basename(cp_path)
        self.cp_image = django_file
        create_watermark(self.cp_image, self.topic, self.text, 500, 45)
        super(MyModel, self).save(*args, **kwargs) #to save my new ImageField

from django.dispatch import receiver
from django.db.models.signals import post_save
@receiver(post_save, sender=MyModel)
def mymodel_slug_handler(sender, instance=None, **kwargs):
    if instance is not None:
        new_slug = '%s-%i' % (instance.topic, instance.id)
        if instance.slug != new_slug: # Stops recursion.
            instance.slug = new_slug
            instance.save()

---

不幸的是，如果我在尝试对文件进行操作之前不使用save（）方法，则会导致“无此类文件或目录：”错误。哦，然后将整个保存移动到post_save处理程序。这还允许您检查created=True，以便只执行一次。