code: def send_file(request, filename, content_type='image/jpeg'):
      
      wrapper = FixedFileWrapper(file(filename, 'rb'))
      response = HttpResponse(wrapper, content_type=content_type)
      response['Content-Length'] = os.path.getsize(filename)
      return response
docs: Send a file through Django without loading the whole file into              
      memory at once. The FileWrapper will turn the file object into an           
      iterator for chunks of 8KB.