How to support dig's @<ip> syntax in python argparse

Question

The linux dig utility allows you to specify the target DNS server with '@ip' syntax, like dig @8.8.8.8 A www.example.com. How can I can support that same syntax support in Python's argparse module? (Installing dnsutils in my container was adding 50MB to my image size, so I'm trying to put together a small and simple resolver with dnspython that mimics my most commonly used dig features.)

#!/usr/local/bin/python
import dns.resolver
import argparse

parser = argparse.ArgumentParser(description='Small and incomplete python replacement for dig.')
#parser = argparse.ArgumentParser(prefix_chars='-@', description='Small and incomplete python replacement for dig.')

parser.add_argument('query_type', nargs='?', default='A', help='The type of record to resolve')
parser.add_argument('url', type=str,
                    help='The URL to resolve')
parser.add_argument('@', dest=dns,
                    help='The DNS server to query.')


if __name__ == "__main__":
    resolver = dns.resolver.Resolver()
    args = parser.parse_args()

    if args.dns:
        print(f'DNS is {args.dns}')
        resolver.nameservers=[args.dns]

    if args.query_type:
        print(f'query_type is {args.query_type}')

    if args.url:
        print(f'url is {args.url}')

    records = resolver.resolve('_imaps._tcp.gmail.com', args.query_type)

    for record in records:
        print(record)