telnet_showIPintbrief.py

#!/usr/bin/env python3.6
'''
Write a script that connects to a Cisco IOS device using telnet, 
and executes the 'show ip int brief' command.
'''
from __future__ import print_function, unicode_literals
import telnetlib
import time
import socket
import sys
import getpass

class MyTelnetlib(object):
    """
    My Telnet library
    """
    def __init__(self):
        self.telnet_port = 23
        self.telnet_timeout = 6

    def send_command(self, remote_conn, cmd):
        '''
        Send a command down the telnet channel
        Return the response
        '''
        cmd = cmd.rstrip()
        remote_conn.write(cmd + '\n')
        time.sleep(1)
        return remote_conn.read_very_eager()

    def login(self, remote_conn, username, password):
        '''
        Login to network device
        '''
        output = remote_conn.read_until("sername:", self.telnet_timeout)
        remote_conn.write(username + '\n')
        output += remote_conn.read_until("ssword:", self.telnet_timeout)
        remote_conn.write(password + '\n')
        return output

    def disable_paging(self, remote_conn, paging_cmd='terminal length 0'):
        '''
        Disable the paging of output (i.e. --More--)
        '''
        return self.send_command(remote_conn, paging_cmd)

    def telnet_connect(self, ip_addr):
        '''
        Establish telnet connection
        '''
        try:
            return telnetlib.Telnet(ip_addr, self.telnet_port, self.telnet_timeout)
        except socket.timeout:
            sys.exit("Connection timed-out")


    def main(self):
        '''
        Write a script that connects to the lab pynet-rtr1, logins, and executes the
        'show ip int brief' command.
        '''
        try:
            ip_addr = raw_input("IP address: ")
        except NameError:
            ip_addr = input("IP address: ")
        ip_addr = ip_addr.strip()
        username = input("Username: ")
        password = getpass.getpass()

        remote_conn = self.telnet_connect(ip_addr)
        output = self.login(remote_conn, username, password)

        time.sleep(1)
        remote_conn.read_very_eager()
        self.disable_paging(remote_conn)

        output = self.send_command(remote_conn, 'show ip int brief')

        print ("\n\n")
        print (output)
        print ("\n\n")

        remote_conn.close()

if __name__ == "__main__":
    EXECUTE = MyTelnetlib()
    EXECUTE.main()