二级域名抓取

import requests
import dns.resolver

def get_subdomains(domain):
    subdomains = set()
    try:
        answers = dns.resolver.resolve(domain, 'CNAME')
        for rdata in answers:
            subdomains.add(str(rdata))
    except dns.resolver.NXDOMAIN:
        print(f"{domain} does not exist.")
    except dns.resolver.NoAnswer:
        print(f"{domain} has no CNAME records.")
    except dns.resolver.Timeout:
        print(f"Timed out while resolving {domain}.")
    
    return subdomains

def main():
    domain = 'example.com'
    subdomains = get_subdomains(domain)
    print(f"Subdomains of {domain}:")
    for subdomain in subdomains:
        print(subdomain)

if __name__ == "__main__":
    main()

dns.resolver.default_resolver.timeout = 5.0
dns.resolver.default_resolver.lifetime = 5.0

dig example.com CNAME +short