aio-timers

aio-timers

Timing utilities based on asyncio.

Setup

pip install aio-timers

Usage

import asyncio
from aio_timers import Timer

def callback(name):
    print("Hello {}!".format(name))

# timer is scheduled here
timer = Timer(5, callback, callback_args=("World",))

# wait until the callback has been executed
loop = asyncio.get_event_loop()
loop.run_until_complete(timer.wait())
print("end")

Output:

(after 5 seconds)

Hello World!

end

Timer

Calls a callback after delay seconds.

The timer is executed as a task on an event loop.

The callback is invoked:

• as a synchronous function if it is not a coroutine;
• with an await if it is a coroutine or the callback_async flag is set to True.

Any result returned by the callback is ignored.

Constructor

Timer(delay, callback, callback_args=(), callback_kwargs={}, callback_async=False, *, loop=None)

where:

• delay, seconds before the callback is executed;
• callback, the callback to execute after delay seconds
• callback_args, (optional, default=()) positional arguments to pass to callback
• callback_kwargs, (optional, default={}) keyword arguments to pass to callback
• callback_async, (optional, default=False) if True the callback will be executed on the event loop (await)
• loop, (optional, default=None) event loop where the delayed task will be scheduled (ifNone will use asyncio.get_event_loop())

NOTE: the callback_async flag should be used when a coroutine is decorated (e.g., using functools.partial)

.cancel()

Cancels the execution of the callback.

async .wait()

Wait until the callback has been executed or its execution has been canceled.

If the execution has been canceled, will raise asyncio.CancelledError.