Choose single result (based on priority & weight)

[OJFord]

I think it'd be nice to add a function (and perhaps use if __name__ == '__main__' too?) that return a single host:port from among the resolved options, according to their priority and weight.

I'd be happy to work a PR if you're interested.

[OJFord]

Just as a proof of concept, something like:

import random
from sys import argv
from srvlookup import lookup


def choose_srv(*args):
    srvs = lookup(*args)

    top_priority_srvs = []
    total_weight = 0
    for srv in srvs:
        if srv.priority == srvs[0].priority:
            top_priority_srvs.append(srv)
            total_weight += srv.weight

    return random.choices(
        population=top_priority_srvs,
        weights=(srv.weight / total_weight for srv in top_priority_srvs),
        k=1,
    )[0]


if __name__ == "__main__":
    args = argv[1:]
    if len(args) == 1:
        args = args[0].split(".", 2)
        for i, arg in enumerate(args[:2]):
            args[i] = arg.lstrip("_")

    srv = choose_srv(*args)
    print(f"{srv.host}:{srv.port}")

Which can then be used as:

curl $(choose-srv _some._thing.foo.bar)

or whatever.