code: def __getitem__(self, idx):
      file_idx = self.data_idx_order_list[idx]
      data_line = self.data_lines[file_idx]
      try:
          data_line = data_line.decode("utf-8")
          substr = data_line.strip("\n").split(self.delimiter)
          file_name = substr[0]
          file_name = self._try_parse_filename_list(file_name)
          label = substr[1]
          img_path = os.path.join(self.data_dir, file_name)
          data = {"img_path": img_path, "label": label}
          if not os.path.exists(img_path):
              raise Exception("{} does not exist!".format(img_path))
          with open(data["img_path"], "rb") as f:
              img = f.read()
              data["image"] = img
          data["ext_data"] = self.get_ext_data()
          outs = transform(data, self.ops)
      except:
          self.logger.error(
              "When parsing line {}, error happened with msg: {}".format(
                  data_line, traceback.format_exc()
              )
          )
          outs = None
      if outs is None:
          # during evaluation, we should fix the idx to get same results for many times of evaluation.
          rnd_idx = (
              np.random.randint(self.__len__())
              if self.mode == "train"
              else (idx + 1) % self.__len__()
          )
          return self.__getitem__(rnd_idx)
      return outs
  
imports: import numpy
  import cv2
  import math
  import os
  import json
  import random
  import traceback
  from paddle.io import Dataset
  from .imaug import transform, create_operators
label_desc: Use image node_id 7 for calling the SimpleDataSet obj's underlying member method code with example usage: obj.__getitem__(idx) and returns: outs, self