Django content type of an image file

问题:

I want to check a file type before uploading it by:

content = self.cleaned_data['picture']
content_type = content.content_type.split('/')[0]

When I upload the picture I get an error:

'NoneType' object has no attribute 'content_type'

What can be wrong here?

回答1:

imghdr.what will return image format as string (gif, png etc.) if the image is valid, or None otherwise.

Usage:

import imghdr
imghdr.what(value)

In the above example value can be either a file(-like) object or a filename.