implement dig command with python

dig.py

#! /usr/bin/env python3
# -*- coding: utf-8 -*-
import sys
import dns.resolver


def check_dns(domain_name: str, dns_server: str):
    # Create a DNS resolver instance and set the nameserver to the DNS server you want to query
    resolver = dns.resolver.Resolver(configure=False)
    resolver.nameservers = [dns_server]

    # Use the resolver to perform a DNS lookup for the domain's IP address
    response = resolver.query(domain_name)

    # Print out the IP addresses associated with the domain name
    for answer in response:
        print(f'{dns_server} reply: {domain_name} is {answer}.')


def main():
    if len(sys.argv) < 3:
        print("Usage: script.py domain @dns_server")
        return

    domain_name = sys.argv[1]
    dns_server = sys.argv[2]

    if dns_server.startswith('@'):
        dns_server = dns_server[1:]
        check_dns(domain_name, dns_server)
    else:
        print("Error: DNS server argument should start with '@'")
        return


if __name__ == "__main__":
    main()