Django缓存-显示从缓存中检索的图像的问题

Question

我使用的是django 1.4、python 2.7、Memcache、python-memcached和easy-thumbnails。

当我试图使用缓存数据访问一个项目页面时，我得到了以下模板错误：

Couldn't get the thumbnail uploads/items/item_images/logo.jpeg: 'ImageFieldFile' object has no attribute 'instance'

当我从shell中的数据库访问有问题的数据时，我会得到：

>>> log = item.get_logo()
>>> logo
<ImageFieldFile: uploads/items/item_images/logo.png>
>>> logo.instance
<Media: uploads/items/item_images/logo.png>

当我试图从缓存中访问相同的数据时，我得到了：

>>> cache.set('logo',item.get_logo())
>>> logo = cache.get('logo')
>>> logo
<ImageFieldFile: uploads/items/item_images/logo.png>
>>> logo.instance
Traceback (most recent call last):
  File "<console>", line 1, in <module>
AttributeError: 'ImageFieldFile' object has no attribute 'instance'

我的问题是，如何缓存ImageFieldFile，使其在原始状态下可检索？我需要将该对象传递给我的模板，以便与简单的缩略图一起使用。

Answer 1

因此，我没有尝试缓存ImageFieldFile，而是缓存了ImageFieldFile所在的对象(Media)，现在一切都正常了。

数据库：

>>> logo = item.get_logo()
>>> logo
<Media: uploads/items/item_images/logo.png>
>>> logo.image #this is what I was trying to cache before
<ImageFieldFile: uploads/items/item_images/logo.png>
>>> logo.image.instance
<Media: uploads/items/item_images/logo.png>

缓存：

>>> cache.set('logo',logo)
>>> cachedLogo = cache.get('logo')
>>> logo
<Media: uploads/items/item_images/logo.png>
>>> logo.image
<ImageFieldFile: uploads/items/item_images/logo.png>
>>> logo.image.instance
<Media: uploads/items/item_images/logo.png>