asynctkinter 0.4.1

Description:

asynctkinter 0.4.1

AsyncTkinter
Youtube
asynctkinter is an async library that saves you from ugly callback-style code,
like most of async libraries do.
Let's say you want to do:

print('A')
wait for 1sec
print('B')
wait for a label to be pressed
print('C')

in that order.
Your code would look like this:
def what_you_want_to_do(label):
bind_id = None
print('A')

def one_sec_later(__):
nonlocal bind_id
print('B')
bind_id = label.bind('<Button>', on_press, '+')
label.after(1000, one_sec_later)

def on_press(event):
label.unbind('<Button>', bind_id)
print('C')

what_you_want_to_do(...)

It's not easy to understand.
If you use asynctkinter, the code above will become:
import asynctkinter as at

async def what_you_want_to_do(clock, label):
print('A')
await clock.sleep(1)
print('B')
await at.event(label, '<Button>')
print('C')

at.start(what_you_want_to_do(...))

Installation
Pin the minor version.
poetry add asynctkinter@~0.4
pip install "asynctkinter>=0.4,<0.5"

Usage
import tkinter as tk
import asynctkinter as at


async def main(*, clock: at.Clock, root: tk.Tk):
label = tk.Label(root, text='Hello', font=('', 80))
label.pack()

# waits for 2 seconds to elapse
await clock.sleep(2)

# waits for a label to be pressed
event = await at.event(label, '<Button>')
print(f"pos: {event.x}, {event.y}")

# waits for either 5 seconds to elapse or a label to be pressed.
# i.e. waits at most 5 seconds for a label to be pressed
tasks = await at.wait_any(
clock.sleep(5),
at.event(label, '<Button>'),
)
if tasks[0].finished:
print("Timeout")
else:
event = tasks[1].result
print(f"The label got pressed. (pos: {event.x}, {event.y})")

# same as the above
async with clock.move_on_after(5) as timeout_tracker:
event = await at.event(label, '<Button>')
print(f"The label got pressed. (pos: {event.x}, {event.y})")
if timeout_tracker.finished:
print("Timeout")

# waits for both 5 seconds to elapse and a label to be pressed.
tasks = await at.wait_all(
clock.sleep(5),
at.event(label, '<Button>'),
)

# nests as you want.
tasks = await ak.wait_all(
at.event(label, '<Button>'),
at.wait_any(
clock.sleep(5),
...,
),
)
child_tasks = tasks[1].result


if __name__ == "__main__":
at.run(main)

threading
Unlike Trio and asyncio, asynctkinter doesn't provide any I/O functionalities,
thus threads may be the best way to perform them without blocking the main thread:
from concurrent.futures import ThreadPoolExecuter
import asynctkinter as at

executer = ThreadPoolExecuter()

async def async_fn(clock: at.Clock):
# create a new thread, run a function inside it, then
# wait for the completion of that thread
r = await clock.run_in_thread(thread_blocking_operation, polling_interval=1.0)
print("return value:", r)

# run a function inside a ThreadPoolExecuter, and wait for its completion.
# (ProcessPoolExecuter is not supported)
r = await clock.run_in_executer(executer, thread_blocking_operation, polling_interval=0.1)
print("return value:", r)

Exceptions(not BaseExceptions) are propagated to the caller,
so you can catch them like you do in synchronous code:
import requests
import asynctkinter as at

async def async_fn(clock: at.Clock):
try:
r = await clock.run_in_thread(lambda: requests.get('htt...', timeout=10), ...)
except requests.Timeout:
print("TIMEOUT!")
else:
print('RECEIVED:', r)

Notes

You may want to read the asyncgui's documentation as it is the foundation of this library.
You may want to read the asyncgui_ext.clock's documentation as well.
I, the author of this library, am not even a tkinter user so there may be plenty of weird code in the repository.