Python 练习3 --定义类，类方法，实例方法

设计一个IP类：

设计1 要求：初始化时给定ip地址并判断ip地址的合法性

            类方法：判断ip地址合法性

            实例方法：将ip地址转化为10进制的表示形式及16进制的表示形式

   例如：192.168.168.8 十进制形式为3232278536，十六进制形式为c0a8a808

设计2 要求：扩展要求1中ip类，使其实例化时增加子网掩码定义，并在初始化是判断子网掩码的合法性

            实例方法：获取ip所属子网的网络号，广播地址，及子网内ip个数

 

设计1解析：

"""Ip address analyzerMethod:dispIp: Display ip address. intIp: Get integer of ip address. hexIp: Get hex of ip address"""from string import Templateclass IpAddress(object):'Ip address analyzer'def __init__(self,ip):'Initialize ip address and netmask'assert IpAddress.isIp(ip),/"ip is invalid"self.ipAddr = ipdef isIp(cls,x):'Determine if the ip address is valid'aList = x.split(".")if len(aList) != 4: return Falseelse:nList=[i for i in aList if (i.isdigit() and 0 <= int(i) <= 255)]if len(nList) != 4: return Falseelse: return TrueisIp=classmethod(isIp)def __bin(self,x):'Convert the decimal into binary,and return 8-bit binary. 'x = int(x)if x == 0:return '00000000'else:re = '' while x > 0: mod = x%2 x = x/2 re = str(mod) + rediffer = 8 - len(re)re = ''.join(['0' for i in range(differ)]) + rereturn redef dispIp(self):'Display ip address'template = Template('IP: ${ipAddr}')print template.substitute(ipAddr=self.ipAddr)def intIp(self):'Return integer of the ip address'aList = self.ipAddr.split(".")str2 = ''.join(self.__bin(i) for i in aList)return str(int(str2, 2))def hexIp(self):'Return hex of the ip address'aList = self.ipAddr.split(".")return ''.join(len(hex(int(i)))==4 and hex(int(i))[2:] or '0'+hex(int(i))[2:] for i in aList)