code: def prettify_json_file(file_list):
      
      for json_file in set(file_list):
          if not json_file.endswith(".json"):
              logger.log_warning("Only JSON file format can be prettified, skip: {}".format(json_file))
              continue
  
          logger.color_print("Start to prettify JSON file: {}".format(json_file), "GREEN")
  
          dir_path = os.path.dirname(json_file)
          file_name, file_suffix = os.path.splitext(os.path.basename(json_file))
          outfile = os.path.join(dir_path, "{}.pretty.json".format(file_name))
  
          with io.open(json_file, 'r', encoding='utf-8') as stream:
              try:
                  obj = json.load(stream)
              except ValueError as e:
                  raise SystemExit(e)
  
          with io.open(outfile, 'w', encoding='utf-8') as out:
              json.dump(obj, out, indent=4, separators=(',', ': '))
              out.write('\n')
  
          print("success: {}".format(outfile))
docs: prettify JSON testcase format