# dependant variables
login = 'your_login'
password = 'your_password'
host = 'your_host'
newline = '\r\n'

from telnetlib import Telnet
tn = Telnet(host, 23)

# login procedure, may vary between telnet servers
print tn.read_until('login:',2),
tn.write(login+newline)
print tn.read_until('password:',2),
tn.write(password+newline)
print tn.read_until('C:\\>')    # especially this line!!

# generate a continuous stream for 20 seconds
tn.write('ping -n 20 -w 1000 1.1.1.1'+newline)
print 'This should only take 5 seconds.'
# test either read_until...
print tn.read_until('nott found!', 5) # hangs
# .. or expect
#print tn.expect(['stat'], 5) # hangs