Script to turn DECnet Area-number and Nodenumber into a MAC-adress for SIMH

convertmactodnet.py

#!/usr/bin/python
#BY SPARCie
import sys, getopt, numpy

firstoctets = 'AA-00-04-00'

def main(argv):
   area = ''
   firstFour = 'AA-00-04-00'
   node = ''
   try:
      opts, args = getopt.getopt(argv,"ha:n:",["area=","node="])
   except getopt.GetoptError:
      print('convertmactodnet.py -a <areanr> -n <nodenr>')
      sys.exit(2)
   for opt, arg in opts:
      if opt == '-h':
         print('convertmactodnet.py -a <areanr> -n <nodenr>')
         sys.exit()convertmactodnet.py
      elif opt in ("-a", "--area"):
         area = arg
      elif opt in ("-n", "--node"):
         node = arg
   area =int(area)
   node = int(node)
   prepcompute = int(area*1024+node)
   compute = str(prepcompute)
   hexprepcomp=hex(prepcompute)
   strMac=str(hexprepcomp)
   strMac=strMac[2:]
   if len(strMac)==3:
       strMac="0"+strMac
   byteOne=strMac[2:].upper()
   byteTwo=strMac[:2].upper()
   decMAC=firstFour+"-"+byteOne+"-"+byteTwo
   print(decMAC)

def swap32(x):
    return int.from_bytes(x.to_bytes(4, byteorder='little'), byteorder='big', signed=False)

if __name__ == "__main__":
   main(sys.argv[1:])

Small typo or copy/paste misser: Line 19