检测域名是否有效

import dns.resolver

def check_domain_validity(domain):
    try:
        # 查询域名的A记录
        answers = dns.resolver.resolve(domain, 'A')
        return True
    except dns.resolver.NXDOMAIN:
        print(f"域名 {domain} 不存在")
    except dns.resolver.NoAnswer:
        print(f"域名 {domain} 没有A记录")
    except dns.resolver.Timeout:
        print(f"查询域名 {domain} 超时")
    except Exception as e:
        print(f"查询域名 {domain} 时发生错误: {e}")
    return False

# 示例调用
domain = "example.com"
if check_domain_validity(domain):
    print(f"域名 {domain} 有效")
else:
    print(f"域名 {domain} 无效")