def _data_file(mode, task_id):
    """Generates the path to the data file for the given mode(train/test).

    Args:
      mode: either train or test for bAbi dataset
      task_id: babi task id

    Returns:
      data file path
    """
    file_name = (_TASKS[task_id] + "_{}.txt")
    return os.path.join(_DIR_NAME, subset, file_name.format(mode))
Generates the path to the data file for the given mode(train/test).

    Args:
      mode: either train or test for bAbi dataset
      task_id: babi task id

    Returns:
      data file path
    
tensor2tensor/data_generators/babi_qa.py