python - Django 'File' 对象没有属性 'content_type'

Question

我正在定义一个函数，为模型中上传的每张图片创建缩略图。下面是我的代码:

def create_thumbnail(self):
     if not self.coverphoto:
         return

     from PIL import Image
     from cStringIO import StringIO
     from django.core.files.uploadedfile import SimpleUploadedFile
     import os

     # Set our max thumbnail size in a tuple (max width, max height)
     THUMBNAIL_SIZE = (200,200)

     DJANGO_TYPE = self.coverphoto.file.content_type

     if DJANGO_TYPE == 'image/jpeg':
         PIL_TYPE = 'jpeg'
         FILE_EXTENSION = 'jpg'
     elif DJANGO_TYPE == 'image/png':
         PIL_TYPE = 'png'
         FILE_EXTENSION = 'png'
     elif DJANGO_TYPE == 'image/gif':
         PIL_TYPE = 'gif'
         FILE_EXTENSION = 'gif'

     # Open original photo which we want to thumbnail using PIL's Image
     image = Image.open(StringIO(self.coverphoto.read()))

     image.thumbnail(THUMBNAIL_SIZE, Image.ANTIALIAS)

     # Save the thumbnail
     temp_handle = StringIO()
     image.save(temp_handle, PIL_TYPE)
     temp_handle.seek(0)

     # Save image to a SimpleUploadedFile which can be saved into
     # ImageField
     suf = SimpleUploadedFile(os.path.split(self.coverphoto.name)[-1],
             temp_handle.read(), content_type=DJANGO_TYPE)
     # Save SimpleUploadedFile into image field
     self.coverphoto_thumbnail.save('%s_thumbnail.%s'%(os.path.splitext(suf.name)[0],FILE_EXTENSION), suf,save=False)

当我运行单元测试时，它显示错误:

'File' object has no attribute 'content_type'

指示的错误行是:

DJANGO_TYPE = self.coverphoto.file.content_type 

因为我从一个旧的 Django 片段中得到了这段代码。我认为这可能是由不同的 django 版本引起的。

我可以知道如何在 Django 1.6 中检查 content_type 吗？

有什么好的方法可以解决问题吗？

谢谢。

Answer 1

    from mimetypes import MimeTypes
    import urllib
    mime = MimeTypes()
    url = urllib.pathname2url(file_name)
    mime_type = mime.guess_type(url)