#tested with Python 3.1.1+ on Ubuntu 9.10
import socket
import sys

sock = socket.socket()

sock.bind(("127.0.0.1", 12345))
sock.listen(5) #magic constant value from tcp server
con = sock.accept()
con = con[0]


print(con.send(bytes("Hello", "ascii")))
print(con.sendall(bytes("Hello", "ascii")))


#PAUSE
sys.stdin.read(1)
# no run
# ncat 127.0.0.1 12345
# and terminate connection after the 'HelloHello' arrived


print(con.send(bytes("Hello", "ascii")))
# this returns 5, no error here

#print(con.sendall(bytes("Hello", "ascii")))
# no error too

con.close()
sock.close()