Python的代码中存在无效参数错误

Question

我试图写一个服务器主要是从类的例子，因为我不知道是怎么回事。我的线路有问题-

(input,output,err)=select.select(socks,[],[])

我得到错误'无效参数'，我不知道如何修复这个。我写的和课堂上一样。有人能帮我吗？谢谢你

  #Server
    import select
    import socket
    import math
    import random



    def within(guess,goal,n):
        absValue = abs(guess - goal)
        if absValue <= n:
            return True
        else:
            return False

    scoreCount = 0
    guess = 0

    s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
    s.bind(("127.0.0.1",9000))
    s.listen(5)

    socks = []

    while True:
        (input,output,err)=select.select(socks,[],[])

        for i in input:
            if (i == s):
                (c,a) = s.accept()
                socks.append(c)
                print ("Received connection from", a)
                hello = c.recv(1024).decode()
                print(hello)
                c.send('Greetings\r\n'.encode())

                goal = random.randrange(1,21)

                while guess!= goal:
                    guess =c.recv(1024).decode()
                    guess = int(guess[7:len(guess)-2])

                    if guess == goal:
                        c.send('correct\r\n'.encode())
                    elif within(guess, goal, 2) == True:
                        c.send('close\r\n'.encode())
                    else:
                        c.send('far\r\n'.encode())
            c.close()