django-storages不會從S3中刪除

Question

使用django-storages package當我刪除一個對象時，它不會從S3文件存儲中刪除圖像。我知道沒有其他物體使用相同的圖像。

有人會知道這裏發生了什麼是有沒有我不知道的默認？

models.py

class Product(models.Model): 
     title = models.CharField(max_length=60,) 
     description = models.TextField(max_length=300,) 
     price = models.DecimalField(max_digits=8, decimal_places=2,) 
     qr_url = models.URLField(blank=True, verbose_name="QR Code URL", help_text="Read only generated automatically.") 
     qr_image = models.ImageField(
      upload_to="qr-codes", 
      height_field="qr_image_height", 
      width_field="qr_image_width", 
      null=True, 
      blank=True, 
      editable=True, 
      verbose_name="QR Code Image" 
     ) 
     qr_image_height = models.PositiveIntegerField(null=True, blank=True, editable=False) 
     qr_image_width = models.PositiveIntegerField(null=True, blank=True, editable=False) 

     #FK 
     category = models.ManyToManyField(ProductCategory) 

def product_pre_save(sender, instance, **kwargs): 
    if not instance.pk: 
     instance._QRCODE = True 
    else: 
     if hasattr(instance, '_QRCODE'): 
      instance._QRCODE = False 
     else: 
      instance._QRCODE = True 

models.signals.pre_save.connect(product_pre_save, sender=Product) 



def product_post_save(sender, instance, **kwargs): 
    if hasattr(instance, '_already_saving'): 
     del instance._already_saving 
     return 
    if instance._QRCODE: 
     instance._QRCODE = False 
    if instance.qr_image: 
     instance.qr_image.delete() 
     # Create url 
    instance.qr_url = instance.create_QR_URL() 
    qr = QRCode(4, QRErrorCorrectLevel.L) 
    qr.addData(instance.qr_url) 
    qr.make() 
    image = qr.makeImage() 


    #Save image to string buffer 
    image_buffer = StringIO() 
    image.save(image_buffer, format='JPEG') 
    image_buffer.seek(0) 

    #Here we use django file storage system to save the image. 
    file_name = 'UrlQR_%s.jpg' % instance.id 
    file_object = File(image_buffer, file_name) 
    content_file = ContentFile(file_object.read()) 
    instance._already_saving = True 
    instance.qr_image.save(file_name, content_file, save=True) 


models.signals.post_save.connect(product_post_save, sender=Product) 

Answer 1

在你post_save行動，你必須：

... 
if instance.qr_image: 
     instance.qr_image.delete() 
... 

這是行不通的，因爲你想刪除一個字段，而不是實例這就是爲什麼Boto不會刪除該文件。

See this answer有關如何使用Boto刪除單個文件的示例。