文件上传后，删除相关信息后，对应的上传文件也同时删除，具体代码可参考如下：
class AgreementList(models.Model):
file=models.FileField(verbose_name="合同附件",upload_to='hetong/%Y/%m')
#删除文件相关库
from django.db.models.signals import pre_delete
from django.dispatch.dispatcher import receiver
#可以删除信息时候自动删除文件
@receiver(pre_delete, sender=AgreementList)
def mymodel_delete(sender, instance, **kwargs):
# Pass false so FileField doesn't save the model.
instance.file.delete(False)