class_docstr: The implement of DialogReader.
code: def _read_numerical_file(self, fp, delimiter=";"):
      for i, line in enumerate(fp):
          cols = (
              tokenization.convert_to_unicode(line)
              .strip()
              .split(delimiter)
          )
          cols = list(map(lambda x: list(map(int, x.split(" "))), cols))
          if len(cols) > self.num_numerical_fields:
              cols = cols[: self.num_numerical_fields]
          tgt_start_idx = cols[0].index(self.bos_id, 1)
          record = self.Record(
              *cols, tgt_start_idx=tgt_start_idx, data_id=i
          )
          yield record
  
imports: import csv
  from collections import namedtuple
  from contextlib import contextmanager
  import gzip
  import numpy
  from ..utils import pad_batch_data
  from ..utils.args import str2bool
  from ..utils.masking import mask
  from ..utils import tokenization
label_desc: Use image node_id 6 for calling the DialogReader obj's underlying member method code with example usage: obj._read_numerical_file(fp, delimiter) without return types