root_servers.py

#!/usr/bin/env python3

import asyncio
import click
import aiohttp
import yaml
from functools import wraps

def coro(f):
    @wraps(f)
    def wrapper(*args, **kwargs):
        return asyncio.run(f(*args, **kwargs))

    return wrapper

LETTERS = [chr(ord('A') + x) for x in range(13)]
URL_TPL = 'https://root-servers.org/root/{}/yaml'


async def get_root_server(session, letter, country, site_type):
    url = URL_TPL.format(letter)

    res = []
    async with session.get(url) as resp:
        content = await resp.text()
        sites = yaml.safe_load(content)
        for site in sites['Sites']:
            if site['Country'] in country and site['Type'] in site_type:
                res.append('{} ({})'.format(site['Town'], site['Type']))

    return (letter, res)

@click.command()
@click.option("--country", default=[],  multiple=True, help="2-letters country code.")
@click.option("--site-type", type=click.Choice(["Global", "Local"]), default=["Global"], multiple=True, help="Which type of entries to print out.")
@coro
async def main(country, site_type):
    async with aiohttp.ClientSession() as session:
        tasks = []
        for letter in LETTERS:
            tasks.append(asyncio.ensure_future(get_root_server(session, letter, country, site_type)))
        results = await asyncio.gather(*tasks)
        for result in results:
            if not len(result[1]):
                continue
            print(result[0] + ":")
            for x in result[1]:
                print("\t{}".format(x))

if __name__ == '__main__':
    main()