code: def _unpack_tarfile(filename, extract_dir):
      
      try:
          tarobj = tarfile.open(filename)
      except tarfile.TarError:
          raise ReadError(
              "%s is not a compressed or uncompressed tar file" % filename)
      try:
          tarobj.extractall(extract_dir)
      finally:
          tarobj.close()
docs: Unpack tar/tar.gz/tar.bz2 `filename` to `extract_dir`