Rudimentary, Sans-IO `https://httpbin.org/get`, with a syncronous implementation on the side

httpbin_sansio_get.py

import json
import h11
from urllib.parse import urlencode


class Get:
    """Sans-IO implementation of `/get`"""

    def __init__(self, params):
        self.params = params

    def to_send(self):
        target = "/get{}{}".format("?" if self.params else "", urlencode(self.params))
        return [
            h11.Request(method="GET", target=target, headers=[("Host", "httpbin.org")]),
            h11.EndOfMessage(),
        ]

    def parse(self, events):
        data = b""
        for event in events:
            if isinstance(event, h11.Data):
                data += event.data

        return json.loads(data.decode("utf-8"))["args"]

httpbin_sync_get.py

import h11
from httpbin_sansio_get import Get

# This client is the functions from h11's example client, as a class.
# See https://gist.github.com/madsmtm/5f3d0b9b5f68e41ff13cb5eaa15868a7
from h11_sync_client import Client


def get(params):
    """Call `/get` with URL-encoded parameters."""
    client = Client("httpbin.org")
    getter = Get(params)

    for event in getter.to_send():
        client.send(event)

    events = []
    while True:
        event = client.next_event()
        events.append(event)
        if isinstance(event, h11.EndOfMessage):
            break

    return getter.parse(events)