def xlsw_write_row(ws, row_idx, row, fmt=None):
    """
    ws:
    row_idx: row number
    row: a list, data to write
    fmt: format for cell
    """
    for col_idx in range(len(row)):
        ws.write(row_idx, col_idx, row[col_idx], fmt)
    row_idx += 1
    return row_idx