code: def _init_nt_hdr(self, line):
          
          line = line.replace('.', '_')
          line = line.replace(' ', '_')
          line = line.replace('#', 'N')
          line = line.replace('-', '_')
          line = line.replace('"', '')
          #line = re.sub(r"_$", r"", line)
          hdrs = re.split(self.sep, line)
          if '' in hdrs:
              hdrs = NCBIgeneFileReader.replace_nulls(hdrs)
          # Init indexes which will be converted to int or float
          self.idxs_int = [idx for idx, hdr in enumerate(hdrs) if hdr in self.int_hdrs]
          self.idxs_float = [idx for idx, hdr in enumerate(hdrs) if hdr in self.float_hdrs]
          assert hdrs[6] == 'Aliases'
          return namedtuple('ntncbi', ' '.join(hdrs))
docs: Convert headers into valid namedtuple fields.