Multithread telnet not working Parallel

[ka06059]

what if u indent lines 52 & 53 ...

with open('zyxel.txt','r') as ipfile:
        for sr_no, line in enumerate(ipfile, start=1):
            ip = line.strip()
            th = threading.Thread(target = open_telnet ,args = (ip,))
            th.start()
            threads.append(th)
        for thr in threads:   #indent this line
            thr.join()        #indent this line

the code likely started & joined each thread simultanously, could be the main reason why scripts works sequentially