How does one use magic to verify file type in a Django form clean method?

Question

I have written an email form class in Django with a FileField. I want to check the uploaded file for its type via checking its mimetype. Subsequently, I want to limit file t

Answer 1

mime = magic.Magic(mime=True)

attachment = form.cleaned_data['attachment']

if hasattr(attachment, 'temporary_file_path'):
    # file is temporary on the disk, so we can get full path of it.
    mime_type = mime.from_file(attachment.temporary_file_path())
else:
    # file is on the memory
    mime_type = mime.from_buffer(attachment.read())

Also, you might want to seek(0) after read():

if hasattr(f, 'seek') and callable(f.seek):
    f.seek(0)

Example from Django code. Performed for image fields during validation.