【Python】判断一个字符串是否是合法IP地址

#!usr/bin/env python
#encoding:utf-8

'''''
__Author__:沂水寒城
功能：判断一个字符串是否是合法IP地址
'''

import re

def judge_legal_ip(one_str):
'''''
正则匹配方法
判断一个字符串是否是合法IP地址
'''
compile_ip=re.compile('^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$')
if compile_ip.match(one_str):
return True
else:
return False

def judge_legal_ip2(one_str):
'''''
简单的字符串判断
'''
if '.' not in one_str:
return False
elif one_str.count('.')!=3:
return False
else:
flag=True
one_list=one_str.split('.')
for one in one_list:
try:
one_num=int(one)
if one_num>=0 and one_num<=255:
pass
else:
flag=False
except:
flag=False
return flag

if __name__=='__main__':
ip_list=['','172.31.137.251','100.10.0.1000','1.1.1.1','12.23.13','aa.12.1.2','12345678','289043jdhjkbh']
for one_str in ip_list:
if judge_legal_ip(one_str):  #正则方法
#if judge_legal_ip2(one_str):  #字符串方法
print '{0} is a legal ip address!'.format(one_str)
else:
print '{0} is not a legal ip address!'.format(one_str)