#!/usr/bin/env python

import getpass
import sys
import telnetlib

HOST = "<IP>"
user = "<USERNAME>"
password = "<PASSWORD>"

tn = telnetlib.Telnet(HOST)

tn.read_until("Username: ")
tn.write(user + "\n")
if password:
    tn.read_until("Password: ")
    tn.write(password + "\n")

tn.write("term len 0\n")
tn.write("show run\n")
tn.write("exit\n")
print(tn.read_all())