python - 关闭文件的 I/O 操作 : Django Imagekit & Pillow

Question

我正在使用 django imagekit 和 pillow 上传在 django 1.7 中运行良好的图像。最近我们转移到 django 1.10，现在图像上传不起作用。代码片段是:

class Images(models.Model):
    image = ProcessedImageField(upload_to='main',
                                processors=[ResizeToCover(640, 640)],
                                format='JPEG',
                                options={'quality': 90})
    image_thumbnail = ProcessedImageField(upload_to='thumbnails',
                                          processors=[SmartResize(128, 128)],
                                          format='JPEG',
                                          options={'quality': 70})
    user = models.ForeignKey(User)

    def upload_image(self, image, user):
        if len(image.name) > 30:
            image.name = image.name[:20]
        i = Images.objects.create(image=image, image_thumbnail=image, user=user)
        return i

回溯是:

File "C:\Python35\lib\site-packages\imagekit\specs\__init__.py" in generate
  149.             img = open_image(self.source)

File "C:\Python35\lib\site-packages\pilkit\utils.py" in open_image
  21.     target.seek(0)

During handling of the above exception (I/O operation on closed file.), another exception occurred:

File "C:\Python35\lib\site-packages\django\core\handlers\exception.py" in inner
  39.             response = get_response(request)

File "C:\Python35\lib\site-packages\django\core\handlers\base.py" in _legacy_get_response
  249.             response = self._get_response(request)

File "C:\Python35\lib\site-packages\django\core\handlers\base.py" in _get_response
  187.                 response = self.process_exception_by_middleware(e, request)

File "C:\Python35\lib\site-packages\django\core\handlers\base.py" in _get_response
  185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Python35\lib\site-packages\django\contrib\auth\decorators.py" in _wrapped_view
  23.                 return view_func(request, *args, **kwargs)

File "C:\Users\sp\industryo\nodes\views.py" in set_logo
  173.             i = Images.objects.create(image=image, user=user, image_thumbnail=image)

File "C:\Python35\lib\site-packages\django\db\models\manager.py" in manager_method
  85.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "C:\Python35\lib\site-packages\django\db\models\query.py" in create
  399.         obj.save(force_insert=True, using=self.db)

File "C:\Python35\lib\site-packages\django\db\models\base.py" in save
  796.                        force_update=force_update, update_fields=update_fields)

File "C:\Python35\lib\site-packages\django\db\models\base.py" in save_base
  824.             updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)

File "C:\Python35\lib\site-packages\django\db\models\base.py" in _save_table
  908.             result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)

File "C:\Python35\lib\site-packages\django\db\models\base.py" in _do_insert
  947.                                using=using, raw=raw)

File "C:\Python35\lib\site-packages\django\db\models\manager.py" in manager_method
  85.                 return getattr(self.get_queryset(), name)(*args, **kwargs)

File "C:\Python35\lib\site-packages\django\db\models\query.py" in _insert
  1043.         return query.get_compiler(using=using).execute_sql(return_id)

File "C:\Python35\lib\site-packages\django\db\models\sql\compiler.py" in execute_sql
  1053.             for sql, params in self.as_sql():

File "C:\Python35\lib\site-packages\django\db\models\sql\compiler.py" in as_sql
  1006.                 for obj in self.query.objs

File "C:\Python35\lib\site-packages\django\db\models\sql\compiler.py" in <listcomp>
  1006.                 for obj in self.query.objs

File "C:\Python35\lib\site-packages\django\db\models\sql\compiler.py" in <listcomp>
  1005.                 [self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]

File "C:\Python35\lib\site-packages\django\db\models\sql\compiler.py" in pre_save_val
  955.         return field.pre_save(obj, add=True)

File "C:\Python35\lib\site-packages\django\db\models\fields\files.py" in pre_save
  292.             file.save(file.name, file, save=False)

File "C:\Python35\lib\site-packages\imagekit\models\fields\files.py" in save
  12.         content = generate(spec)

File "C:\Python35\lib\site-packages\imagekit\utils.py" in generate
  134.     content = generator.generate()

File "C:\Python35\lib\site-packages\imagekit\specs\__init__.py" in generate
  153.             self.source.open()

File "C:\Python35\lib\site-packages\django\db\models\fields\files.py" in open
  81.         self.file.open(mode)

File "C:\Python35\lib\site-packages\django\core\files\uploadedfile.py" in open
  96.         self.file.seek(0)

Exception Type: ValueError at /nodes/set_logo/
Exception Value: I/O operation on closed file.

这里可以做什么。我需要对包进行更改吗？帮助!

Answer 1

似乎 Imagekit 和 Pillow 在最新版本中的交互不是很好。可以看出问题的发生是因为imagekit发送的文件不能被PIL直接处理。

因此，为了裁剪和改变尺寸和质量，我们完全转向了 PIL。

def upload_image1(self, image, user, name, image1):

        if len(image1.name) > 30:
            image1.name = image1.name[:20]
        i = Images.objects.create(image=image1, user=user)
        new_image_io = BytesIO()
        image.save(new_image_io, format='JPEG')
        i.image_thumbnail.save(name, content=ContentFile(new_image_io.getvalue()))
        return i

要创建缩略图，我们必须打开图像并将其保存为此处:

new_image_io = BytesIO()
image.save(new_image_io, format='JPEG')
i.image_thumbnail.save(name, content=ContentFile(new_image_io.getvalue()))

希望对您有所帮助!