for ckpt_file in ckpt_files:
    saver.restore(sess, dir_path + ckpt_file)
global_step = ckpt.model_checkpoint_path.split('/')[-1].split('-')[-1]
print('Succesfully loaded model from %s at step=%s.' % (ckpt.
    model_checkpoint_path, global_step))
tensorflow: run model evaluation over multiple checkpoints