continue loop even if one host is not available

import time

import paramiko

import sys

from getpass import getpass

#First Unifi AP IP Address
firstip=3

fistdigits = '10.0.0.'

#how can we prevent from crashing if 10.0.0.19 is not an available device
while firstip<=100:

    host= f'{fistdigits}{firstip}'
    #first one will be 10.0.0.3 then 10.0.0.4 etc

    username="username"
    password="password"

    session= paramiko.SSHClient()

    session.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    session.connect(hostname=host,
                   username=username,
                   password=password)

    #upgradeurl="https://dl.ui.com/unifi/firmware/U7PG2/4.3.13.11253/BZ.qca956x.v4.3.13.11253.200430.1420.bin"
    #stdin, stdout, stderr = session.exec_command("upgrade "+{upgradeurl})
    stdin, stdout, stderr = session.exec_command("reboot")

    output=stdout.read()
    print(output)
    print("Command executed for device:   "+host)
    firstip +=1
    time.sleep(.5)
    print(stdout.read().decode())


session.close()

>Solution :

Use try except? – https://docs.python.org/3/tutorial/errors.html#handling-exceptions

import time

import paramiko

import sys

from getpass import getpass

#First Unifi AP IP Address
firstip=3

fistdigits = '10.0.0.'

#how can we prevent from crashing if 10.0.0.19 is not an available device
while firstip<=100:

    host= f'{fistdigits}{firstip}'
    #first one will be 10.0.0.3 then 10.0.0.4 etc

    username="username"
    password="password"

    try:

        session= paramiko.SSHClient()

        session.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        session.connect(hostname=host,
                       username=username,
                       password=password)

        #upgradeurl="https://dl.ui.com/unifi/firmware/U7PG2/4.3.13.11253/BZ.qca956x.v4.3.13.11253.200430.1420.bin"
        #stdin, stdout, stderr = session.exec_command("upgrade "+{upgradeurl})
        stdin, stdout, stderr = session.exec_command("reboot")

        output=stdout.read()
        print(output)
        print(stdout.read().decode())
        print("Command executed for device:   "+host)
    except TimeoutError as e:
        print("Exception occurred while interacting with host {}: {}".format(host, e))
    finally:
        session.close()
    firstip +=1
    time.sleep(0.5)