Python chat program instance code sharing

The code is simple. Check the Code directly:
Copy codeThe Code is as follows:
Import socket
Import threading
Import re
# Import Tkinter

Def ser ():
S = socket. socket (socket. AF_INET, socket. SOCK_STREAM)
S. bind ('', 33333 ))
S. listen (1)
Conn, addr = s. accept ()
While True:
Print '[% s: % d] send a message to me: % s' % (addr [0], addr [1], conn. recv (1024 ))
S. close ()

Def clt ():
C = socket. socket (socket. AF_INET, socket. SOCK_STREAM)
Ip_pattern = re. compile (R' ^ (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) \. (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) \. (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) \. (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) $ ')
While True:
Ip = raw_input ('input the Server \'s IPv4 address :')
Ip_match = ip_pattern.match (ip)
If ip_match:
Break
C. connect (ip, 33333 ))
While True:
Sms = raw_input ('input the message you want to send :')
C. sendall (sms)
C. close ()

If _ name __= = "_ main __":
Ser = threading. Thread (target = ser)
Clt = threading. Thread (target = clt)
Ser. start ()
Clt. start ()
Ser. join ()
Clt. join ()