python socket编程--以十六进制格式发送字节流

import socket
import time
import struct
MaxBytes=1024*1024
host ='192.168.0.5'
port = 8888
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
client.settimeout(30
client.connect((host,port))
# str=[0x00,0x03,0x00,0x00,0x00,0x06,0xff,0x03,0x00,0x04,0x00,0x0c]#12字节
str="000300000006FF030004000C"#12字节
# str1 = "\x00\x03\x00\x00\x00\x06\xff\x03\x00\x04\x00\x0c"
str2 = bytes()
str1= ""
while str:
    str1 = str[0:2]
    s = int(str1, 16)
    str2 += struct.pack('B', s)
    str = str[2:]
while True:
    inputData=input();          #等待输入数据
    if(inputData=="quit"):
        print("我要退出了，再见")
        break
    # alfreddata = bytes()
    # for i in range(len(str)):
    #     alfreddata += struct.pack('B', str[i])
    sendBytes = client.send(str2)
    #sendBytes = client.send(b"\x00\x03\x00\x00\x00\x06\xff\x03\x00\x04\x00\x0c")
    #sendBytes = client.sendall(b'\xff')
    if sendBytes<=0:
        break;
    recvData = client.recv(MaxBytes)
    if not recvData:
        print('接收数据为空，我要退出了')
        break
    localTime = time.asctime( time.localtime(time.time()))
    print(localTime, ' 接收到数据字节数:',len(recvData))
    print(recvData)
client.close()
print("我已经退出了，后会无期")

笔记：
1、import struct，引用struct这个模块
2、str2 = bytes()，发送的二进制字节流，用bytes初始化
3、str2 += struct.pack('B', s)，把ascii编码转成十六进制后，用struct.pack把字节流拼接起来