usr bin env python3 Converts IP PREFIX lines from stdin and input file

#!/usr/bin/env python3

# Converts IP/PREFIX lines from stdin and input files
# to stdout in P2P Block format suitable for import
# into Torrent clients such as qBitTorrent.
#
# Originally posted here:
#    https://www.reddit.com/r/torrents/comments/bdme4i

from fileinput import input
import ipaddress

i = 1
for line in input():
  candidate = line.strip()
  try:
    network = ipaddress.ip_network(candidate)
  except ValueError:
    continue
  else:
    if network.prefixlen < 32:
      hosts = network.hosts()
      first_ip = next(hosts)
      last_ip = (first_ip + (network.num_addresses - 3))
    elif network.prefixlen == 32:
      first_ip = network.network_address
      last_ip = first_ip
    else: # shouldn't get here
      continue
    print('net{}:{}-{}'.format(i, first_ip, last_ip))
    i += 1