题解 | #验证IP地址#

#分类讨论就行
class Solution:
    def solve(self , IP: str) -> str:
        def is_hex(s):
            try:
                int(s, 16)
                return True
            except ValueError:
                return False
        def check_ip4(s):
            if s.isdigit():
                if -1<int(s)<256:
                    if len(s)==1:
                        return True
                    elif len(s)>1 and s[0] != '0':
                        return True
            return False
        def check_ip6(s):
            if is_hex(s):
                if len(s) > 1 and s == ''.zfill(len(s)):
                    return False
                return True
            return False
        if '.' in IP:
            ip = IP.split('.')
            for i in ip:
                if not check_ip4(i):
                    return 'Neither'
            return 'IPv4'
        else:
            ip = IP.split(':')
            for i in ip:
                if not check_ip6(i):
                    return 'Neither'
            return 'IPv6'