1. 下面的例子，客户端给服务端发送消息，服务端把消息返回

#!/usr/bin/env pythonimport selectorsimport socketimport timeimport threadingsel = selectors.DefaultSelector()def echo(conn,cmd,filename):    time.sleep(3)    conn.send((cmd + ‘ ‘ + filename).encode())def accept_client(sock,mask):    conn,addr = sock.accept()    print(‘conn:{},addr:{},mask:{}‘.format(conn,addr,mask))#     conn.setblocking(False)    sel.register(conn, selectors.EVENT_READ, read_client)def read_client(conn,mask):    data = conn.recv(1024).decode().strip()    if data:        if len(data.split(‘ ‘)) == 2:            cmd = data.split(‘ ‘)[0]            filename = data.split(‘ ‘)[1]            t = threading.Thread(target=echo,args=(conn,cmd,filename))   #这里使用了线程，不然程序会变成串行的，执行一个客户端任务，sleep(3)然后再执行下一个客户端任务...            t.start()#             time.sleep(1)#             conn.send((cmd + ‘ ‘ + filename).encode())        else:            conn.send((‘usage: put filename ;get filename‘).encode())    else:        print(‘{} closed‘.format(conn))        sel.unregister(conn)        conn.close()server = socket.socket()server.bind((‘localhost‘,1235))server.listen(12340)# server.setblocking(False)sel.register(server, selectors.EVENT_READ,accept_client)while True:    events = sel.select()    for key,mask in events:        callable = key.data        callable(key.fileobj,mask)

#!/usr/bin/env pythonimport socketimport threadingimport timeip_port = (‘localhost‘,1235)socks = [socket.socket() for i in range(1000)]        m = b‘get abc‘time_list = []def run(s):    s.connect(ip_port)    s.send(m)    data = s.recv(1024)    print(s,data)    start_time = time.time()   for s in socks:    t = threading.Thread(target=run,args=(s,))    t.start()    time_list.append(t)for i in time_list:    i.join()print(‘time:{}‘.format(start_time - time.time()))