code: def to_internal_value(self, data):
          
          course_id = data
          course_video = image = ''
          if data:
              if isinstance(data, dict):
                  (course_id, image), = list(data.items())
  
              course_video = CourseVideo(course_id=course_id)
              course_video.full_clean(exclude=['video'])
  
          return course_video, image
docs: Convert data into CourseVideo instance and image filename tuple.