Python 3: create a list of possible ip addresses from a CIDR notation

Question

I have been handed the task of creating a function in python (3.1) that will take a CIDR notation and return the list of possible ip addresses. I have looked around python.

Answer 1

I would prefer to do a little math rather than to install an external module, no one has the same taste with me?

#!/usr/bin/env python
# python cidr.py 192.168.1.1/24

import sys, struct, socket

(ip, cidr) = sys.argv[1].split('/')
cidr = int(cidr) 
host_bits = 32 - cidr
i = struct.unpack('>I', socket.inet_aton(ip))[0] # note the endianness
start = (i >> host_bits) << host_bits # clear the host bits
end = start | ((1 << host_bits) - 1)

# excludes the first and last address in the subnet
for i in range(start, end):
    print(socket.inet_ntoa(struct.pack('>I',i)))