test_telnet.py

#!/usr/bin/env python

import telnetlib
import time
import socket
import sys

TELNET_PORT = 23
TELNET_TIMEOUT = 6

def send_command(remote_conn, cmd):
    cmd = cmd.rstrip()
    remote_conn.write(cmd + '\n')
    time.sleep(1)
    return remote_conn.read_very_eager()

def login(remote_conn, username, password):
    output = remote_conn.read_until("sername:", TELNET_TIMEOUT)
    remote_conn.write(username + '\n')
    output += remote_conn.read_until("ssword:", TELNET_TIMEOUT)
    remote_conn.write(password + '\n')
    return output

def telnet_connect(ip_addr, TELNET_PORT, TELNET_TIMEOUT):
    try:
        remote_conn = telnetlib.Telnet(ip_addr, TELNET_PORT, TELNET_TIMEOUT)
        return remote_conn
    except socket.timeout:
        sys.exit("Connection timed out")

def main():
    ip_addr = '50.76.53.27'
    username = 'pyclass'
    password = '88newclass'
    
    remote_conn = telnet_connect(ip_addr, TELNET_PORT, TELNET_TIMEOUT)
    output = login(remote_conn, username, password)
    output += remote_conn.read_very_eager()
    output += send_command(remote_conn, 'terminal length 0')
    output += send_command(remote_conn, 'show ver')

    print output

    remote_conn.close()

if __name__ == "__main__":
    main()