python - socket を使ったプロセス間通信

#!/usr/bin/env python
# -*- coding: sjis -*-

import os
import sys
import threading
from socket import socket, AF_INET, SOCK_STREAM

# AF_INET =  Adress Family : Internet Sockets IPv4 を指す
# SOCK_STREAM = 通信プロトコル TCP を使用。 SOCK_DGRAM だと UDP

port = 50008
host = 'localhost'

stdoutmutex = threading.Lock()

def server():
    sock = socket(AF_INET, SOCK_STREAM)
    sock.bind(('', port)) # アドレスとポートを指定. '' は 'localhost' に置き換えても同じ模様
    sock.listen(5) # 同時に接続できる個数
    while True:
        conn, addr = sock.accept()
        data = conn.recv(1024) # bufsize
        with stdoutmutex:
            print data
        reply = 'server got : [%s]\n' % data
        conn.send(reply.encode())

def client(name):
    sock = socket(AF_INET, SOCK_STREAM)
    sock.connect((host, port))
    sock.send(name.encode())
    reply = sock.recv(1024)
    sock.close()
    with stdoutmutex:
        print 'client got : [%s]' % reply

if __name__=='__main__':
    argv = sys.argv
    if len(argv) <= 1:
        sys.exit(1)
    elif argv[1] == '-s':
        sthread = threading.Thread(target=server)
        sthread.daemon = False
        sthread.start()
    elif argv[1] == '-c':
        for i in range(5):
            threading.Thread(target=client, args=('client % s' % i,)).start()