code: def __init__(self, dirname, label="phoneme"):
      self.dirname = dirname
      assert os.path.isdir(dirname), dirname
      self.filelists = [
          k
          for k in fs.recursive_walk(self.dirname)
          if k.endswith(".wav")
      ]
      logger.info("Found {} wav files ...".format(len(self.filelists)))
      assert len(self.filelists), "Found no '.wav' files!"
      assert label in ["phoneme", "letter"], label
      self.label = label
  
imports: import argparse
  import numpy
  import os
  import string
  import bob.ap
  import scipy.io.wavfile
  from tensorpack.dataflow import DataFlow, LMDBSerializer
  from tensorpack.utils import fs, logger, serialize, get_tqdm
  from tensorpack.utils.argtools import memoized
  from tensorpack.utils.stats import OnlineMoments
label_desc: Use image node_id 1 to create a new RawTIMIT object from inherited base classes: DataFlow with example: obj = RawTIMIT(dirname, label)