How to use callback async?

[Chimildic]

Need to register global hotkeys. For example, f4 and f8. With keyboard library while first callback didn't return, the next won't call.

Another words, logs like this

pressed f4
end for f4
pressed f8
end for f8

But I want to like this

pressed f4
pressed f8
end for f4
end for f8

Demo code

# pip install keyboard
from keyboard import add_hotkey, wait
from time import sleep

def on_callback(key):
    print('pressed', key)
    sleep(5)
    print('end for', key)

add_hotkey("f4", lambda: on_callback("f4"))
add_hotkey("f8", lambda: on_callback("f8"))

wait('esc')

I tried to use asyncio, but nothing changed

pressed f4
end for f4
pressed f8
end for f8

from keyboard import add_hotkey, wait
import asyncio

async def on_callback(key):
    print('pressed', key)
    await asyncio.sleep(5)
    print('end for', key)

add_hotkey("f4", lambda: asyncio.run(on_callback("f4")))
add_hotkey("f8", lambda: asyncio.run(on_callback("f8")))

wait('esc')

[boppreh]

Callbacks are executed in the same thread, sequentially, so two callbacks with 5 seconds of sleep each result in one long thread sleeping 10 seconds. Asyncio may have helped if you were not using sleep, which doesn't yield to the event loop.

The easiest solution is to spawn a new thread on each callback, so that they can sleep separately. You use keyboard.call_later for this, which by default sleeps only a few milliseconds:

# pip install keyboard
from keyboard import add_hotkey, wait, call_later
from time import sleep

def on_callback(key):
    print('pressed', key)
    sleep(5)
    print('end for', key)

add_hotkey("f4", lambda: call_later(on_callback, args=("f4",)))
add_hotkey("f8", lambda: call_later(on_callback, args=("f8",)))

wait('esc')

[Chimildic]

sleep in order to emulate long task for demo.
Can you write example with asyncio?

[boppreh]

The asyncio version of sleep is asyncio.sleep, as detailed here: https://stackoverflow.com/questions/56729764/python-3-7-asyncio-sleep-and-time-sleep

However I'm not sure it'll play well with the rest of keyboard, since the library is thread-based. I would keep the call_later functions, they should work for other long running tasks other than sleep.

[Chimildic]

Yeah, call_later works correctly. I ask you about

Asyncio may have helped if you were not using sleep

In my case, async didn't happen

add_hotkey(item["keys"], lambda: asyncio.run(_on_callback(item["function"])))

async def _on_callback(function):
    response = await _script.run(function)

async def run(self, function: str):
    # ...
    return self.service.run(scriptId=self._id, body=body)