Write Spreadsheet with openpyxl

def write_spreadsheet(xls_file, record_list, overwrite=True):
    """

    :param xls_file: output filename
    :param record_list: [ [ 'r1f1', 'r1f2' ], [ 'r2f1', 'r2f2' ] ]
    :param overwrite: Flag for overwriting the output file in case it exists, or appending records
    :return:
    """
    if overwrite:
        add_record_xls_workbook = openpyxl.Workbook()
    else:
        if os.path.exists(xls_file):
            add_record_xls_workbook = openpyxl.load_workbook(xls_file)
        else:
            add_record_xls_workbook = openpyxl.Workbook()

    # grab the active worksheet
    active_sheet = add_record_xls_workbook.active

    # append row
    for row in record_list:
        active_sheet.append(row)

    # Save the file
    add_record_xls_workbook.save(xls_file)