从url中提取域名

from urllib.parse import urlparse

def extract_domain(url):
    parsed_url = urlparse(url)
    domain = parsed_url.netloc
    return domain

# 示例
url = "https://www.example.com/path/to/resource?query=param"
print(extract_domain(url))  # 输出: www.example.com

function extractDomain(url) {
    const parsedUrl = new URL(url);
    return parsedUrl.hostname;
}

// 示例
const url = "https://www.example.com/path/to/resource?query=param";
console.log(extractDomain(url));  // 输出: www.example.com

import java.net.URI;
import java.net.URISyntaxException;

public class DomainExtractor {
    public static String extractDomain(String url) throws URISyntaxException {
        URI uri = new URI(url);
        String domain = uri.getHost();
        return domain != null ? domain : "";
    }

    public static void main(String[] args) {
        try {
            String url = "https://www.example.com/path/to/resource?query=param";
            System.out.println(extractDomain(url));  // 输出: www.example.com
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
    }
}

import re

def is_valid_url(url):
    regex = re.compile(
        r'^(?:http|ftp)s?://'  # http:// or https://
        r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # domain...
        r'localhost|'  # localhost...
        r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'  # ...or ip
        r'(?::\d+)?'  # optional port
        r'(?:/?|[/?]\S+)$', re.IGNORECASE)
    return re.match(regex, url) is not None

# 示例
url = "https://www.example.com/path/to/resource?query=param"
if is_valid_url(url):
    print(extract_domain(url))
else:
    print("Invalid URL")

def extract_domain(url):
    parsed_url = urlparse(url)
    domain = parsed_url.netloc.split(':')[0]  # 去除端口号
    return domain