code: def _retrieve_ptb_words(name, url):
      def creator(path):
          vocab = _retrieve_word_vocabulary()
          words = _load_words(url)
          x = numpy.empty(len(words), dtype=numpy.int32)
          for i, word in enumerate(words):
              x[i] = vocab[word]
  
          numpy.savez_compressed(path, x=x)
          return {"x": x}
  
      root = download.get_dataset_directory("pfnet/chainer/ptb")
      path = os.path.join(root, name)
      loaded = download.cache_or_load_file(path, creator, numpy.load)
      return loaded["x"]
  
file_path: chainer/chainer/datasets/ptb.py
imports: import os
  import numpy
  from chainer.dataset import download
label_desc: Use image node_id 3 for calling a global function with example usage: _retrieve_ptb_words(name, url) and returns: loaded, dict