Napalm example

napalm.py

#!/usr/bin/env python3

from napalm import get_network_driver
from getpass import getpass
from netmiko import NetMikoAuthenticationException
from napalm.base.exceptions import ConnectionException
from pprint import pprint


username = input('username: ')
password = getpass('password: ')
driver = get_network_driver('ios')
with open('devices.txt','r') as switch_db:
    for switch in switch_db:
    #set up to connect to a switch from switch_db
        try:
            with driver(switch, username, password, optional_args={'port': 8181}) as device:
                pprint(device.get_facts())
        except NetMikoAuthenticationException:
            print('Authentication Error!')
        except ConnectionException:
            print(f'Could not connect to {switch}')

updated to handle the errors a bit better.