def column_names(sheet, formatter=str):

    """
    Get the ordered column names from an XLRD sheet object

    :param sheet: XLRD sheet object
    :type sheet: xlrd.Sheet
    :param formatter:
    :type formatter: type|function

    :return: list of column names
    :rtype: list
    """

    return [formatter(cell.value) for cell in sheet.row(0)]