python3判断IP地址的方法

import re
def isIP(str):
 p = re.compile('^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$')
 if p.match(str):
  return True
 # else:
 #  return False
myStr = input()
if isIP(myStr):
 print(IP(myStr).strHex().upper())
 # ip = list(map(int, myStr.split('.')))
 # print('0x', end='')
 # for i in ip:
 #  print(hex(i)[2:].upper().rjust(2, '0'), end='')
else:
 print('Error')

def change(lis):
 if len(lis)!=4:
 return 'Error'
 try:    # 判断字符串是否存在非数字
 lis=[int(i) for i in lis]
 except:
 return 'Error'
 for i in lis:
 if i<0 or i>255: # 判断ip地址是否合法
 return 'Error'
 temp='0x'   #记录16进制数
 for i in lis:
 a=hex(int(i))[2:].upper().rjust(2,'0') #转换为16进制
 # if len(a)!=2:
 # a='0'+a
 temp+=a
 return temp
s=list(map(str,input().split('.')))
print(change(s))

l = input().split(".")
if len(l) != 4:
 print("Error")
else:
 s = ""
 for i in l:
  try:
   num = int(i)
   if num > 255 or num < 0:
    print("Error")
    s = ""
    break
   else:
    s += hex(num)[2:].upper().rjust(2, "0")
  except ValueError:
   print("Error")
   s = ""
   break
 if s:
  print("0x" + s)