TypeError: expected string or Unicode object, NoneType found

Question

两个python脚本，一个是socket服务端，一个是客户端。
使用进程池来多进程运行，报错： multiprocessing.Pool ==> TypeError: expected string or Unicode object, NoneType found
(请无视我的烂代码)
具体代码如下：

• 服务端：

import socket
import multiprocessing


def get_mac(cli, caddr):
    while True:
        macinfo = cli.recv(1024)
        if macinfo:
            print('get [{}] from {}'.format(macinfo, caddr))
        else:
            print('establish but get nothing from {}'.format(caddr))
            print('TERMINAL CLI-SOCKET')
            cli.close()
        cli.sendall('Done')
        log.info('Send Confirm <Done> To {}'.format(caddr))
        info = macinfo.split(',').strip()
        return info

def gen_config(info):
    print(info)


def start(func):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    addr = ('mn0', 1995)
    sock.bind(addr)
    sock.listen(5)
    pool = multiprocessing.Pool()
    while True:
        print('waitting for new connect ...')
        cli, caddr = sock.accept()
        print('establish new connect with {}'.format(caddr))
        pool.apply_async(func, args=(cli, caddr,), callback=gen_config)

    pool.close()
    pool.join()


if __name__ == '__main__':
    start(get_mac)

• 客户端：

#!/usr/bin/env python

import socket

def send():
    addr = ('mn0', 1995)
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(addr)
    print('Establish Connect with {}'.format(addr))
    sock.sendall('{},{}'.format('192.168.85.1', 'da:ad:as:as:as:sa'))
    print('send 192.168.85.1  da:ad:as:as:as:sa')
    data = sock.recv(1024)
    if data == 'Done':
       print('Confirm Send')
    sock.close()

if __name__ == '__main__':
    send()

Answer 1

客户端代码

    sock.sendall('{},{}'.format('192.168.85.1', 'da:ad:as:as:as:sa'))

改成

 b = '{},{}'.format('192.168.85.1', 'da:ad:as:as:as:sa');
    sock.sendall(b.encode())

如果查看套接字文档，可以看到sendall需要发送字节。Python有一个内置函数将String转换为字节，称为encode。所以，你必须使用

  sock.sendall(message.encode()) 

将其转换为字节，以便可以发送。