Python检测端口IP字符串是否合法

def is_ip(ip: str) -  bool:
  return True if [True] * 4 == [x.isdigit() and 0 <= int(x) <= 255 for x in ip.split(".")] else False

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

def checkip(hostip):
  pat = re.compile(r'([0-9]{1,3})\.')
  r = re.findall(pat,hostip+".")
  if len(r)==4 and len([x for x in r if int(x) =0 and int(x)<=255])==4:
    return True
  else:
    return False