python生成一个sector数据

def get_oem_bootmode():
    SECTOR_SIZE_IN_BYTES = 512   # Header size

    header = [0 for i in range(SECTOR_SIZE_IN_BYTES)]

    # magic
    header[0:7] = [ord('p'),ord('i'), ord('d'), ord('9'),
                   ord('0'),ord('9'), ord('1'), ord('0')]


    output = StringIO.StringIO()
    for i in header:
        output.write(struct.pack("B", i))
    content = output.getvalue()
    output.close()

    # only need 512 bytes
    return content[:512]