python的单线程多任务的实现

# coding:utf-8from socket import *# 1.创建服务器socketsock = socket(AF_INET, SOCK_STREAM)# 2.绑定主机和端口addr = ('', 7788) #sock.bind(addr)# 3. 设置最大监听数目，并发sock.listen(10)# 4. 设置成非阻塞sock.setblocking(False)# 保存客户端socketclientAddrList = []# print(sock.)while 1:  try:    clientSocket, clientAddr = sock.accept()  except:    pass  else:    print("一个新客户端到来：%s" % str(clientAddr))    clientSocket.setblocking(False)    clientAddrList.append((clientSocket, clientAddr))  for clientSocket, clientAddr in clientAddrList:    try:      recvData = clientSocket.recv(1024)    except:      pass    else:      if len(recvData) > 0:        print("%s:%s" % (str(clientAddr), recvData))      else:        clientSocket.close()        clientAddrList.remove((clientSocket, clientAddr))        print("%s 已经下线" % str(clientAddr))