docstr: Return a filename of a file containing a binary representation of
  target.  If no such file exists, make one.
docstr_tok: ["Return","a","filename","of","a","file","containing","a","binary","representation","of","target",".","If","no","such","file","exists",",","make","one","."]
code: def _target_filename(self, target):
      """
      Return a filename of a file containing a binary representation of
      target.  If no such file exists, make one.
      """
      target_filename = self._target_filenames.get(target)
      if target_filename is None:
          target_filename = os.path.join(
              self.out_dir, "labels", str(target) + ".txt"
          )
          ensure_dirs_exist(target_filename)
          np.savetxt(target_filename, [target], "%d")
          self._target_filenames[target] = target_filename
  
      return target_filename
  
imports: from builtins import str, zip
  from configargparse import ArgParser
  from itertools import repeat
  from neon import logger
  from neon.util.persist import ensure_dirs_exist
  from PIL import Image
  import logging
  import multiprocessing
  import numpy
  import os
  import re
  import shutil
  import tarfile
  import tqdm
  import zlib
label_desc: Use image node_id 2 for calling the IngestI1K obj's underlying member method code with example usage: obj._target_filename(target) and returns: target_filename