Async code example

script.py

import asyncio
import itertools
import aionursery

PRELOADER_SYMBOLS = [
    '|',
    '/',
    '—',
    '\\',
]


async def countdown(count, prefix=''):
    for secs_left in range(count, 0, -1):
        print(f'{prefix}Осталось {secs_left} секунд')
        raise Exception('fixme')
        await asyncio.sleep(1)
    return 'result'


async def show_preloader(prefix=''):
    for symbol in itertools.cycle(PRELOADER_SYMBOLS):
        print(f'{prefix}{symbol}', '\u001b[1A')
        try:
            await asyncio.sleep(0.1)
        except asyncio.CancelledError as exc:
            print('got it', type(exc))
            print('stopping... 3')
            await asyncio.sleep(1)
            print('stopping... 2')
            await asyncio.sleep(1)
            print('stopping... 1')
            await asyncio.sleep(1)
            raise exc


async def run_timer(prefix=''):
    async with aionursery.Nursery() as nursery:
        nursery.start_soon(countdown(10, prefix=prefix))
        nursery.start_soon(show_preloader(prefix=prefix))


async def async_main():
    
    try:
        async with aionursery.Nursery() as nursery:
            nursery.start_soon(run_timer())
            nursery.start_soon(run_timer(prefix=' ' * 30))
    except aionursery.MultiError as exc:
        print('Got error', type(exc))

    print('Done')


if __name__ == '__main__':
    try:
        asyncio.run(async_main())
    except KeyboardInterrupt:
        pass