Simple native Python 3 IP subnet calculator, no dependencies required. Inspired by http://jodies.de/ipcalc.

ipcalc.py

import sys, ipaddress


address = None
interactive = False

if len(sys.argv) > 1:
    address = sys.argv[1]
else:
    address = input('Network: ')
    interactive = True

try:
    address = ipaddress.IPv4Interface(address)

    # Script doesn't support prefixes >31
    if address.network.prefixlen >= 31:
        raise ValueError
    
except ValueError:
    print('Invalid input.', file=sys.stderr)
    sys.exit(1)


network = address.network


output = f"""\
Address:   {address.ip}
Netmask:   {address.netmask}
Wildcard:  {address.hostmask}
===========================
Network:   {network}
Broadcast: {network.broadcast_address}
HostMin:   {network[1]}
HostMax:   {network.broadcast_address-1}
Hosts/Net: {network.num_addresses-2}\
"""

print(output)
if interactive:
    input()