import multiprocessing
import time
import sys
import os

class MyServer(multiprocessing.Process):
    def __init__(self, c2s, s2c):
        multiprocessing.Process.__init__(self)
        self.c2s = c2s
        self.s2c = s2c
    
    def run(self):
        print('%s initialized' % multiprocessing.current_process().name)
        while True:
            msg = self.c2s.get()
            if msg['op'] == 'order':
                print('Server: Received an order: %s.' % msg['content'])
                self.s2c.put({'op':'ok'})
            elif msg['op'] == 'chat':
                print('Server: I am Server! I am replying to 【%s】' % msg['content'])
                self.s2c.put({'op':'ok'})
            elif msg['op'] == 'close':
                print('Server: Closing...')
                self.s2c.put({'op':'close'})
                break
            time.sleep(0.5)

class MyClient(multiprocessing.Process):
    ops = ['order', 'close', 'chat', 'ok']

    def __init__(self, c2s, s2c, fn):
        multiprocessing.Process.__init__(self)
        self.c2s = c2s
        self.s2c = s2c
        self.fn = fn
    
    def run(self):
        sys.stdin = os.fdopen(self.fn)
        print('%s initialized' % multiprocessing.current_process().name)
        while True:
            inp = input('>')
            inp = inp.split(':')
            if len(inp)==2 and inp[0] in self.ops:
                self.c2s.put({'op':inp[0],'content':inp[1]})
            msg = self.s2c.get()
            if msg['op']=='close':
                break
            time.sleep(0.5)

if __name__ == '__main__':
    c2s = multiprocessing.Queue()
    s2c = multiprocessing.Queue()
    server = MyServer(c2s, s2c)
    server.daemon = True
    server.start()
    fn = sys.stdin.fileno()
    client = MyClient(c2s, s2c, fn)
    client.daemon = False
    client.start()

    server.join()
    client.join()

思路

1. 一个服务进程，一个客户进程，通过队列进行通信。
2. 客户进程接收用户消息，并向服务进程发送消息。服务进程根据消息中的’op’对’content’做相应的处理。
3. 用户输入格式为：[op:content]，进程间传递的消息如下：

{'op':'xxx', 'content':'xxx'}

运行结果

MyServer-1 initialized
MyClient-2 initialized
>chat:hello
Server: I am Server! I am replying to 【hello】
>order:sing a song
Server: Received an order: sing a song.
>close:.
Server: Closing...

关键点

1. multiprocessing的使用，如果直接用Process类的话，需要传入一个target函数，如果用现在这种方式实现的话，就写在run方法里面
2. 要实现在client里输入，必须要用到下面这句，否则会出错

sys.stdin = os.fdopen(self.fn)