如何根据IPv4正则表达式正确匹配变量

import re

def match_ipv4_address(ip):
    pattern = r'^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$'
    if re.match(pattern, ip):
        return True
    else:
        return False

ip_address = "192.168.0.1"
if match_ipv4_address(ip_address):
    print("IPv4地址格式正确")
else:
    print("IPv4地址格式错误")

import java.util.regex.Pattern;
import java.util.regex.Matcher;

public class Main {
    public static void main(String[] args) {
        String ip = "192.168.0.1";
        String pattern = "^(?:[0-9]{1,3}\\.){3}[0-9]{1,3}$";
        Pattern regex = Pattern.compile(pattern);
        Matcher matcher = regex.matcher(ip);
        if (matcher.matches()) {
            System.out.println("IPv4地址格式正确");
        } else {
            System.out.println("IPv4地址格式错误");
        }
    }
}