text: from __future__ import print_function, division
  import os
  import sys
  import subprocess
  
  def class_process(dir_path, class_name):
    class_path = os.path.join(dir_path, class_name)
    if not os.path.isdir(class_path):
      return
  
    for file_name in os.listdir(class_path):
      video_dir_path = os.path.join(class_path, file_name)
      image_indices = []
      for image_file_name in os.listdir(video_dir_path):
        if 'image' not in image_file_name:
          continue
        image_indices.append(int(image_file_name[6:11]))
  
      if len(image_indices) == 0:
        print('no image files', video_dir_path)
        n_frames = 0
      else:
        image_indices.sort(reverse=True)
        n_frames = image_indices[0]
        print(video_dir_path, n_frames)
      with open(os.path.join(video_dir_path, 'n_frames'), 'w') as dst_file:
        dst_file.write(str(n_frames))
  
  
  if __name__=="__main__":
    dir_path = sys.argv[1]
    for class_name in os.listdir(dir_path):
      class_process(dir_path, class_name)
  
    class_name = 'test'
    class_process(dir_path, class_name)
  