#!/usr/bin/env python3
# ip-summarize - print summarized CIDR masks for a given IP address range
import argparse
import ipaddress

parser = argparse.ArgumentParser()
parser.add_argument("first_addr")
parser.add_argument("last_addr")
args = parser.parse_args()

try:
    first  = ipaddress.ip_address(args.first_addr)
    last   = ipaddress.ip_address(args.last_addr)
    ranges = ipaddress.summarize_address_range(first, last)
    for net in ranges:
        print(net)
except ValueError as e:
    exit("error: %s" % (e,))
