进程池|线程池（同步，异步  阻塞，非阻塞） 多线程：IO密集型 多进程：计算密集型 线程是cpu运行单位，进程是资源单位

from socket import *from threading import Threaddef comunicat(conn):    while True:  # 通信循环        try:            data = conn.recv(1024)            if len(data) == 0: break            conn.send(data.upper())        except ConnectionResetError:            break    conn.close()def server(ip, port, backlog=5):    server = socket(AF_INET, SOCK_STREAM)    server.bind((ip,port))    server.listen(backlog)    while True:  # 链接循环        conn, client_addr = server.accept()        print(client_addr)        #通信        t=Thread(target=comunicat,args=(conn,))        t.start()if __name__ == '__main__':    s=Thread(target=server,args=('127.0.0.1',8081))    s.start()

from socket import *client=socket(AF_INET,SOCK_STREAM)client.connect(('127.0.0.1',8081))while True:    msg=input(">>:").strip()    if len(msg) == 0: continue    client.send(msg.encode('utf-8'))    data=client.recv(1024)    print(data.decode('utf-8'))

实现在服务端开启时，可以运行多个客户端，但是有一万个客户端时，服务端会开多个线程来运行，这样就会很耗资源