python网络编程中第二章例子2-1，使用自环接口的UDP服务器....

最近学习python，在《python网络编程》这本书中第二章2-1例子：使用自环接口的UDP服务器和客户端有点困惑

1. #!/usr/bin/env python3
   
2. # Foundations of Python Network Programming,Third Edition
   
3. # UDP client and server on localhost
   
4. 
   
5. import argparse,socket
   
6. from datetime import datetime
   
7. 
   
8. MAX_BYTES = 65535
   
9. 
   
10. def server(port):
    
11.         sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    
12.         sock.bind(('127.0.0.11',port))
    
13.         print('Listening at {}',format((sock.getsockname())))
    
14.         while True:
    
15.                 data,address = sock.recvfrom(MAX_BYTES)
    
16.                 text = data.decode('ascii')
    
17.                 print('The client at {} says {!r}'.format(address,text))
    
18.                 text = 'Your data was {} bytes long '.format(len(data))
    
19.                 data = text.encode('ascii')
    
20.                 sock.sendto(data,address)
    
21. 
    
22.                
    
23. def dlient(port):
    
24.         sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    
25.         text = 'The time is {}'.format(datetime.now())
    
26.         data = text.encode('ascii')
    
27.         sock.sendto('127.0.0.1',port)
    
28.         print('The os assigned me the address {}'.format(sock.getsockname()))
    
29.         data,address = sock.recvfrom(MAX_BYTES)#Danger!
    
30.         text = data.decode('ascii')
    
31.         print('The server {} replied (!r)'.format(address,port))
    
32. 
    
33. 
    
34.        
    
35.        
    
36.         if __name__ == '__main__':
    
37.                 choices = {'client': client ,'server': server}  #
    
38.                 parser = argparse.ArgumentParser(description ='Send and receive UDP locally')
    
39.                 parser.add_argument('role',choices=choices,help ='Which role to play')
    
40.                 parser.add_argument('-p',metavar='port',type=int , default=1060,help = 'UDP port (default 1060)')
    
41.                 args= parser.parse_args()
    
42.                 function = choices[args.role]
    
43.                 function(args.p)

复制代码

提示D:\py\python_test\UDP_CS>python udp_local.py client
Traceback (most recent call last):
  File "udp_local.py", line 34, in <module>
    choices = {'client':client, 'server':server}
NameError: name 'client' is not defined

但是一直没找到原因 ，书上的例子中并没有对字典中的键值进行定义。如果把值得类型改为str的在functin(args.p)中会提示无法调用str类型，请问是代码有缺漏还是缩进哪里有不对。

好了 我山炮了。定义的函数居然写错成dlient