Python socket超时

#server.py
import socket
s=socket.socket()
s.bind(('127.0.0.1',2000))
s.listen(5)
while 1:
    cs,address=s.accept()
    cs.settimeout(5)
    print 'got cinnected from',address
    cs.send('hello I am server,weclome')
    ra=cs.recv(512)
    print ra
    cs.close()
当连接建立后，没有动作

got cinnected from ('127.0.0.1', 60701)
Traceback (most recent call last):
File "server.py", line 10, in <module>
ra=cs.recv(512)
socket.timeout: timed out

#client.py
import socket
s=socket.socket()
s.connect(('127.0.0.1',2000))
#s.sendall('hello server!')
data=s.recv(512)
print 'the data received is\n    ',data
#s.send('hihi I am client')
raw_input()
s.close()
输出

the data received is
hello I am server,weclome

Python初学，如有错误，欢迎评论指出，不甚感激。