code: def main():
    
    parser = argparse.ArgumentParser(
        description='Reads in a .xls file and generates a units module for '
                    'OpenHTF.',
        prog='python units_from_xls.py')
    parser.add_argument('xlsfile', type=str,
                        help='the .xls file to parse')
    parser.add_argument(
        '--outfile',
        type=str,
        default=os.path.join(os.path.dirname(__file__), os.path.pardir,
                             'openhtf','util', 'units.py'),
        help='where to put the generated .py file.')
    args = parser.parse_args()
  
    if not os.path.exists(args.xlsfile):
      print('Unable to locate the file "%s".' % args.xlsfile)
      parser.print_help()
      sys.exit()
  
    unit_defs = unit_defs_from_sheet(
        xlrd.open_workbook(args.xlsfile).sheet_by_name(SHEET_NAME),
        COLUMN_NAMES)
  
    _, tmp_path = mkstemp()
    with open(tmp_path, 'w') as new_file:
      new_file.write(PRE)
      new_file.writelines(
          [line.encode('utf8', 'replace') for line in unit_defs])
      new_file.write(POST)
      new_file.flush()
  
    os.remove(args.outfile)
    shutil.move(tmp_path, args.outfile)
docs: Main entry point for UNECE code .xls parsing.