python script for scanning open ports

#!/usr/bin/python3
#
#   This code is of no use for you if you are not a beginner in python3
#   Uploading it just for beginners.......
#   Helps in understanding how port scanners works ..?
#   and basic usage of Thread from threading module
#   This code is long but it's coded this way...
#   Try to optimize this on your own as far as you wanna go with it ...
#
from time import time as cputime,ctime as Time          # IMPORTING LIBS
import socket
from threading import Thread
##
#   Checking for vuln versions using a file containing a list of services and vuln versions...(COMMENTED OUT BY DEFAULT)
##
def check_vuln(reply):          # DEFINE :  CHECK_VULN FUNCTION
#
#   input for file path
#
    path=input('Enter path for file')
    f=open("%s"%path,'r')
    for line in f.readlines():
        #print("LINE: ",line.rstrip('\n'))
        if line.rstrip('\n') in str(reply):
            print("Known vuln service found -> \n\t",str(reply))
        #else:
        #   print("check vuln manually")
##
#   Grabbing banner from services ruuning
##
def grab_banner(ip,port,path):      # DEFINE:GRAB_BANNER
    try:                            # TRY TO AONNECT AND GRAB BANNERS FOR ACTIVE SERVICES/PORTS
        socket.setdefaulttimeout(5)
        s=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((ip, port))       # IF NO ERROR ON THIS ONE THEN THE PORT IS ACTIVE( may be filtered )
        print("[+]IP : PORT -> %s: %s"%(ip,port))
        s.send(b"GARBAGE VALUE bsjvcvsdgvjsbj/anything\r\n")    # sent in bytes type
        banner=s.recv(1024).decode('utf-8')                     # recieved in bytes and converted to str type...
        print(banner)                               # printing recieved banner
        #check_vuln(banner)     # uncomment this and provide file.txt path if u get a match to vuln versions ..
        s.shutdown()
        s.close()
        return banner
    except Exception as e:
        pass
        #print("[-]Connection failed -> IP:%s PORT:%s"%(ip,port))
#
def main(): # DEFINE:MAIN FOR PARSING INPUT AND calling defined FUNC.YOU CAN ADD ARGUMENT PARSING BY YOURSELF... :P
#
# input ip and check if range is passed..?
#
    try:
        ip=input('Enter ip/ip-range: ')
        if '-' in ip:
            temp=ip.split('.')
            ip_range=temp[3].split('-')
            ip_list=[]
            for ip in range(int(ip_range[0]),int(ip_range[1])+1):
                ip_list.append(temp[0]+'.'+temp[1]+'.'+temp[2]+'.'+str(ip))
            ip=ip_list
#
#input port and check if range is passed..?
#
        port=input('Enter port/port-range: ')
        if '-' in port:
            temp=port
            port_range=port.split('-')
            port_list=[]
            for port in range(int(port_range[0]),int(port_range[1])+1):
                port_list.append(port)
            port=port_list
#
#   recording EXEC time here
#
        start_time=cputime()
#
#IN-CASE:-Specific IP and PORT
#
        if type(ip) is type(port) is str:
            thread=Thread(target=grab_banner, args=(ip,port))   #comment these two lines to stop threading
            banner=thread.start()                               # if u want to cmpare exec time
            #banner=grab_banner(ip,port)                        #uncomment this if commented above two lines ...
            if banner:
                print(ip+' '+port)
#
##IN-CASE:-IP-Range and Port-Range passed
#
        elif type(ip) is type(port) is list:
            for x in ip:
                for y in port:
                    thread=Thread(target=grab_banner, args=(x,y))   #comment these two lines to stop threading
                    banner=thread.start()                           # if u want to cmpare exec time
                    #banner=grab_banner(x,y)                        #uncomment this if commented above two lines ...
                    if banner:
                        print(x,' ',y,' : ',banner)
#
##IN-CASE:-Port-Range with specific IP
#
        elif type(ip) is str and type(port) is list:
            for y in port:
                thread=Thread(target=grab_banner, args=(ip,y))  #comment these two lines to stop threading
                banner=thread.start()                           # if u want to cmpare exec time
                #banner=grab_banner(ip,y)                       #uncomment this if commented above two lines ...
                if banner:
                    print(ip,' ',y,' : ',banner)
#
##IN-CASE:-IP-Range and Specific PORT
#
        elif type(ip) is list and type(port) is str:
            for x in ip:
                thread=Thread(target=grab_banner, args=(x,port))    #comment these two lines to stop threading
                banner=thread.start()                               # if u want to cmpare exec time
                #banner=grab_banner(x,port)                         #uncomment this if commented above two lines ...
                if banner:
                    print(x,' ',port,' : ',banner)
#
#
##IN-CASE:- Invalid input type provided
#
    except Exception as e:
        print("\nusage: python3 script.py \ninput-ip:192.168.1.25 or 192.168.1.1-225 ")
        print("input-port:25 or 1-64535\n")
        exit(0)
    finally:
        print("Time-taken:%2f"%(cputime()-start_time))
if __name__ == '__main__':
    main()
#
#
#   Sample output( Banner print commented out):
#
#   n0bit4@n0bit4:~/python_snippets# python3 port_scan.py
#   Enter ip/ip-range: 127.0.0.1
#   Enter port/port-range: 1-20000
#   [+]IP : PORT -> 127.0.0.1: 22
#   [+]IP : PORT -> 127.0.0.1: 80
#   [+]IP : PORT -> 127.0.0.1: 3306
#   [+]IP : PORT -> 127.0.0.1: 7070
#   Time-taken:7.939755