def text_filepaths_for_task(self, tmp_dir, task_id):
    """List of input filepaths for a particular training or dev shard.

    Args:
      tmp_dir: a string
      task_id: an integer less than self.num_shards
    Returns:
      a list of tuples (filepath, start_pos, num_bytes)
    """
    assert task_id >= 0
    assert task_id < self.num_train_shards + self.num_dev_shards
    if task_id < self.num_train_shards:
      return [
          f for i, f in enumerate(self.train_text_filepaths(tmp_dir))
          if i % self.num_train_shards == task_id
      ]
    else:
      return [
          f for i, f in enumerate(self.dev_text_filepaths(tmp_dir))
          if i % self.num_dev_shards == task_id - self.num_train_shards
      ]
List of input filepaths for a particular training or dev shard.

    Args:
      tmp_dir: a string
      task_id: an integer less than self.num_shards
    Returns:
      a list of tuples (filepath, start_pos, num_bytes)
    
tensor2tensor/data_generators/text_problems.py