根据ip地址和子网掩码计算网段地址和广播地址（原创）

Python里有一个专门处理该类问题的IP类库，来看看：

#! /usr/bin/env python

import sys
from IPy import IP

address = sys.argv[1]
netmask = sys.argv[2]

#print address,netmask

#help(IP)
networkAddress = IP(address).make_net(netmask) # init a IP instance, can with netmask directly, or use make_net(netmask)
bcastAddress = IP(networkAddress).broadcast() # return the broadcast ip address

print networkAddress
print bcastAddress