code: def _read_header_lines(base_record_name, dir_name, pb_dir):
      
      file_name = base_record_name + '.hea'
  
      # Read local file
      if pb_dir is None:
          with open(os.path.join(dir_name, file_name), 'r') as fp:
              # Record line followed by signal/segment lines if any
              header_lines = []
              # Comment lines
              comment_lines = []
              for line in fp:
                  line = line.strip()
                  # Comment line
                  if line.startswith('#'):
                      comment_lines.append(line)
                  # Non-empty non-comment line = header line.
                  elif line:
                      # Look for a comment in the line
                      ci = line.find('#')
                      if ci > 0:
                          header_lines.append(line[:ci])
                          # comment on same line as header line
                          comment_lines.append(line[ci:])
                      else:
                          header_lines.append(line)
      # Read online header file
      else:
          header_lines, comment_lines = download._stream_header(file_name,
                                                                pb_dir)
  
      return header_lines, comment_lines
docs: Read the lines in a local or remote header file.
  
      Parameters
      ----------
      base_record_name : str
          The base name of the WFDB record to be read, without any file
          extensions.
      dir_name : str
          The local directory location of the header file. This parameter
          is ignored if `pb_dir` is set.
      pb_dir : str
          Option used to stream data from Physiobank. The Physiobank
          database directory from which to find the required record files.
          eg. For record '100' in 'http://physionet.org/physiobank/database/mitdb'
          pb_dir='mitdb'.
  
      Returns
      -------
      header_lines : list
          List of strings corresponding to the header lines.
      comment_lines : list
          List of strings corresponding to the comment lines.