Simple arp scanner written in python (Scapy module)

Arp-Scanner.py

#! /usr/bin/python

#Author == @avicoder 

import sys,getopt

r = '\033[31m' #red
b = '\033[34m' #blue
g = '\033[32m' #green
y = '\033[33m' #yellow
m = '\033[34m' #magenta
c = '\033[36m' #cyan


def main(argv):
	if len(sys.argv) < 5:
		print m+"\nInvalid Arguments"
		print b+ 'arp.py -i <interface> -r <ip range>'
		sys.exit()


	interface=''
	ip_range=''

	try:
		opts, args = getopt.getopt(argv,"hi:r:",["iface=","ips="])
	except KeyInterrupt:
		print 'arp.py -i <interface> -r <ip range>'
		sys.exit(1)
	for opt,arg in opts:
		if opt=='-h':
			print b+ 'arp.py -i <interface> -r <ip range>'
			sys.exit()
		elif opt in ("-i","--iface"):
			interface=arg
		elif opt in ("-r","--ips"):
			ip_range=arg
		

	print y+"\nScanning ..."
	from scapy.all import srp,Ether,ARP,conf
	conf.verb=0
	ans,uans=srp(Ether(dst="FF:FF:FF:FF:FF:FF")/ARP(pdst=ip_range),timeout=2,iface=interface,inter=0.1)
	for snd,rcv in ans:
	        print c+rcv.sprintf(r"%Ether.src% - %ARP.psrc%")
	print m+"\nScan complete"



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

Can you give a sample test case. As to how this program works.