django使用后台admin修改/删除记录的同时更新文件

# 模型类
class ProjectTable(models.Model):
    # # 附件
    enclosure = models.FileField(upload_to='project', verbose_name='附件', null=True, blank=True)  # 附件

    class Meta:
        db_table = 'project'
        verbose_name = '项目表'
        verbose_name_plural = verbose_name

    def __str__(self):
        return self.name
    pass


import os
from django.dispatch import receiver
from django.db.models.signals import post_delete
from django.conf import settings

## 添加监听器
@receiver(post_delete, sender=模型类)
def delete_upload_files(sender, instance, **kwargs):
    files = getattr(instance, '文件字段')
    if not files:
        return
    fname = os.path.join(settings.MEDIA_ROOT, str(files))
    if os.path.isfile(fname):
        os.remove(fname)
    pass

# 第二种
@receiver(pre_delete, sender=模型类)
def delete(sender, instance, **kwargs):
    instance.文件字段.delete(False)

#修改时
@receiver(post_init, sender=模型类名)
def file_path(sender, instance, **kwargs):
    instance._current_file = instance.文件字段
@receiver(post_save, sender= Company)
def delete_old_image(sender, instance, **kwargs):
    if hasattr(instance, '_current_file'):
        if instance._current_file != instance.文件字段.path:
            instance._current_file.delete(save=False)