          self.images.images_found = images
          self.faces.num_faces_detected = faces
  
      def extract_single_process(self):
          """ Run extraction in a single process """
          frame_no = 0
          for filename in tqdm(self.images.input_images, file=sys.stdout):
 
</s> remove         self.alignments.write_alignments(self.faces.faces_detected)

 </s> add         self.write_alignments()
    def write_alignments(self):
        self.alignments.write_alignments(self.faces.faces_detected)


          self.images.images_found = images
          self.faces.num_faces_detected = faces
  
    def write_alignments(self):
        self.alignments.write_alignments(self.faces.faces_detected)


      def extract_single_process(self):
          """ Run extraction in a single process """
          frame_no = 0
          for filename in tqdm(self.images.input_images, file=sys.stdout):
keep keep add keep keep keep keep
 alignments.json save interval for extracting (#477)

* implement save interval 
scripts/extract.py