asyncio without with bare hands

main.py

from itertools import islice
from collections import deque
from math import sqrt
import time
import asyncio

def lucas():
    yield 2
    a = 2
    b = 1
    while True:
        yield b
        a, b = b, a + b

async def search(iterable, predicate):
    for item in iterable:
        if await predicate(item):
            return item
        await asyncio.sleep(0)
    raise ValueError("Not Found")

async def is_prime(x):
    if x < 2:
        return False
    for i in range(2, int(sqrt(x)) + 1):
        if x % i == 0:
            return False
        await asyncio.sleep(0)
    return True

async def print_matches(iterable, predicate):
    for item in iterable:
        matches = await predicate(item)
        if matches:
            print(f"Found: {item}")

async def repetitive_message(message, interval_seconds):
    while True:
        print(message)
        await asyncio.sleep(interval_seconds)



async def twelve_digit_prime(x):
    return (await is_prime(x)) and (len(str(x)) == 12)

async def monitored_search(iterable, predicate, future):
    try:
        found_item = await search(iterable, predicate)
    except ValueError as not_found:
        future.set_exception(not_found)
    else:
        future.set_result(found_item)

async def montitor_future(future, interval_seconds):
    while not future.done():
        print("Waiting...")
        await asyncio.sleep(interval_seconds)
    print("Done")


loop = asyncio.get_event_loop()
co_obj = search(lucas(), twelve_digit_prime)
search_task = asyncio.ensure_future(co_obj, loop=loop)
monitor_task = asyncio.ensure_future(montitor_future(search_task, 1.0), loop=loop)

search_and_monitor_future = asyncio.gather(search_task, monitor_task)
loop.run_until_complete(search_and_monitor_future)

print(search_task.result())
loop.close()

from https://www.youtube.com/watch?v=M-UcUs7IMIM