Thread error

Hi guys,
when I close the application I get the following error:

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Traceback (most recent call last):
File "main.py", line 88, in <module>
while exit : pass
KeyboardInterrupt
Unhandled exception in thread started by
Error in sys.excepthook:

Original exception was:
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This is the code:
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# Echo client program
import socket
import sys
import thread
import mtalk

HOST = '192.168.0.115' # The remote host
PORT = 3580 # The same port as used by the server

buff = ""
buffStatus = 0
s = None
exit = 1

############### keywordDataIn ###############
def keywordDataIn():
global buff, buffStatus, exit
talkmsg = mtalk.TalkMessage()
while exit:
line = sys.stdin.readline()
if line == 'quit\n':
exit = 0
break
elif line != '\n':
lock.acquire()
buff = talkmsg.Make(line)
buffStatus = 1
lock.release()
elif line == '\n':
pass

############### dataToServer ###############
def dataToServer():
global buff, buffStatus, exit
while exit:
if buffStatus == 1:
try:
lock.acquire()
s.sendall(buff)
buff = ""
buffStatus = 0
lock.release()
except: socket.error
pass # errore da controllare

############## dataFromServer ##############
def dataFromServer():
global exit
while exit:
data = s.recv(1024)
print 'Received', repr(data)


############### Main ###############
if __name__ == "__main__" :

for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC,
socket.SOCK_STREAM):
af, socktype, proto, canonname, sa = res

buffStatus = 0

try:
s = socket.socket(af, socktype, proto)
except socket.error, msg:
print("Unexpected error")
s = None
sys.exit(1)

try:
s.connect(sa)
print 'Connection ...'
except socket.error, msg:
print("The server was not reachable")
s.close()
s = None
sys.exit(1)

print 'Connected'

# mutex
lock = thread.allocate_lock()
thread.start_new_thread(keywordDataIn, ())
thread.start_new_thread(dataToServer, ())
thread.start_new_thread(dataFromServer, ())

while exit : pass

s.close()
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Tnx