code: def corpus_files_for_shard(
      shard_num, train_shards, dev_shards, data_prefix
  ):
      corpus_files = [
          filename
          for i, filename in enumerate(all_corpus_files(data_prefix))
          if i % (train_shards + dev_shards) == shard_num
      ]
      tf.logging.info(
          "Corpus files for shard %s: %s", shard_num, corpus_files
      )
  
      assert shard_num < (train_shards + dev_shards)
      return corpus_files
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import math
  import os
  import random
  import re
  import subprocess
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import text_encoder
  import tensorflow.compat.v1
label_desc: Use image node_id 19 for calling a global function with example usage: corpus_files_for_shard(shard_num, train_shards, dev_shards, data_prefix) and returns: corpus_files