[FIXED] Create dummy asyncio.Task

Issue

How can I create dummy Task object that will be immediately done?

Why?

I often check if task is not None and task.done() just to check if another task can be spawn and feel it's a boilerplate that can be avoided:

def __init__(self):
    self._do_something_task: Optional[asyncio.Task] = None

async def _do_something(self):
    await asyncio.sleep(10)
    # something

def trigger_do_something(self):
    if self._do_something_task is not None and self._do_something_task.done():
        asyncio.create_task(self._do_something())

Currently my workaround is:

def __init__(self):
    self._do_something_task: asyncio.Task = asyncio.create_task(asyncio.sleep(0))

async def _do_something(self):
    await asyncio.sleep(10)
    # something

def trigger_do_something(self):
    if self._do_something_task.done():
        asyncio.create_task(self._do_something())

but I feel its not very readable at the first glance.

Solution

Python is a language with duck typing, so as long as some object can answer if it's done(), it should do the job:

class DummyTask:
    def done(self):
        return True


print(DummyTask().done())  # True

More smart way to do it is to use mock library.

Answered By - Mikhail Gerasimov