How to use await c input in Python

Question

I'm stuck here a little bit with surely a simple thing. Briefly about the problem:
- connected asyncio
- Created 2 async user_io and task_manager cortices
- In user_io () there is an input that is completely ignored by await
- task_manager () is executed only after the completion of user_io ()
Attention question - How to make waiting for input and other korutiny "parallel"?
Thanks for the help!

# Ждёт пользовательский ввод async def user_io(): try: # Ждём действия от пользователя while True: # Await, который ниже не работает! command = await input('Введите команду (С to EXIT): ') if re.match(r'[cC]', command): break except KeyboardInterrupt: print('Скрипт остановлен по комбинации клавиш') # Корутина, выполняемая параллельно с ожиданием пользовательского ввода async def task_manager(): await asyncio.sleep(1) print("I'm a task manager 1!") await asyncio.sleep(1) print("I'm a task manager 2!") if __name__=="__main__": # Запускаем цикл событий loop = asyncio.get_event_loop() tasks = [ loop.create_task(user_io()), loop.create_task(task_manager()) ] loop.run_until_complete(asyncio.wait(tasks)) loop.close() sys.exit()

example of asynchronous input waiting using prompt_toolkit - jfs

Sergey Gornostaev Sergey Gornostaev 53.3k 6 28 66 · Accepted Answer · 2018-02-21T18:04:14

input() is a blocking function. Calling blocking functions in asynchronous code blocks the event loop. Therefore, they must be run in a separate thread. Yes, and the interruption from the keyboard you do not catch in the asynchronous code. In an amicable way, you need to assign a handler by calling the add_signal_handler () method, but this does not work on Windows.

 import asyncio import signal def shutdown(): # Отменяем все задачи, кроме вызвавшей for task in asyncio.Task.all_tasks(): if task is not asyncio.tasks.Task.current_task(): task.cancel() async def user_io(): loop = asyncio.get_event_loop() # Ждём действия от пользователя while True: # Запускаем input() в отдельном потоке и ждём его завершения command = await loop.run_in_executor(None, input, 'Для выхода введите C:\n') if command.lower() == 'c': shutdown() # Отменяем все задачи break # и выходим из цикла # Сопрограмма, выполняемая параллельно с ожиданием пользовательского ввода async def task_manager(): counter = 0 while True: try: await asyncio.sleep(1) except asyncio.CancelledError: break # Выходим из цикла, если задачу отменили counter += 1 print("I'm a task manager {}!".format(counter)) if __name__ == '__main__': # Устанавливаем обработчик Ctrl+C signal.signal(signal.SIGINT, lambda n, f: shutdown()) # Запускаем цикл событий loop = asyncio.get_event_loop() # Задача ждущая завершения сопрограм user_io и task_manager main_task = asyncio.wait([user_io(), task_manager()]) try: loop.run_until_complete(main_task) except asyncio.CancelledError: # Позволяем main_task завершиться loop.run_until_complete(main_task) loop.close()

@AndrioSkur firstly, specifically in Python, getting the benefit of using threads is even harder because of GIL.
Secondly, threads consume significantly more resources than a cycle of events.
Thirdly, writing stable multi-threaded code is much more difficult.
They are waiting for the race, deadlocks, violation of invariants and other pain.
Finally, as Alan Cox said, streaming is necessary for those who cannot program finite automata :)
1- your code already uses (default executor) 2- when waiting for GIL input, usually 3 words are automatically released about situations in which such hacks are useful when shutting down, for future readers
3 - Are you run_until_complete about canceling tasks and re-calling run_until_complete ?
Just one of the ways to stop tasks that are in an infinite loop and complete the work of the event loop so that it does not curse on unhandled exceptions and unfinished futures.

How to use await c input in Python

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