I tried something like ipython/ipykernel#323 (comment) but it looks like "background" tasks are run only when await statement is executed?
Python 3.7.0 (default, Jul 15 2018, 10:44:58)
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IPython 7.0.0.dev -- An enhanced Interactive Python. Type '?' for help.
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In [1]: import asyncio
...:
...: async def aprint(*args):
...: print(*args)
...:
...: asyncio.ensure_future(aprint("background future"))
Out[1]: <Task pending coro=<aprint() running at <ipython-input-1-c3f9a8264358>:3>>
In [2]:
In [2]:
In [2]: await aprint("foreground")
background future
foregroundAlso, asyncio.create_task does not work:
In [3]: asyncio.create_task(aprint("background task"))
---------------------------------------------------------------------------
RuntimeError Traceback (most recent call last)
<ipython-input-3-6787ab5b49b6> in <module>
----> 1 asyncio.create_task(aprint("background task"))
/usr/lib64/python3.7/asyncio/tasks.py in create_task(coro)
318 Return a Task object.
319 """
--> 320 loop = events.get_running_loop()
321 return loop.create_task(coro)
322
RuntimeError: no running event loopReading
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Non-Asynchronous code |
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~~~~~~~~~~~~~~~~~~~~~ |
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As the internal API of IPython are now asynchronous, IPython need to run under |
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an even loop. In order to allow many workflow, (like using the ``%run`` magic, |
I thought the event loop is always running. But it's not the case, right?
In [4]: asyncio.get_event_loop()
Out[4]: <_UnixSelectorEventLoop running=False closed=False debug=False>
In [5]: async def print_loop():
...: print(asyncio.get_event_loop())
In [6]: await print_loop()
<_UnixSelectorEventLoop running=True closed=False debug=False>
I was expecting running=True in Out[4].
Checked with 73d6335
I tried something like ipython/ipykernel#323 (comment) but it looks like "background" tasks are run only when
awaitstatement is executed?Also,
asyncio.create_taskdoes not work:In [3]: asyncio.create_task(aprint("background task")) --------------------------------------------------------------------------- RuntimeError Traceback (most recent call last) <ipython-input-3-6787ab5b49b6> in <module> ----> 1 asyncio.create_task(aprint("background task")) /usr/lib64/python3.7/asyncio/tasks.py in create_task(coro) 318 Return a Task object. 319 """ --> 320 loop = events.get_running_loop() 321 return loop.create_task(coro) 322 RuntimeError: no running event loopReading
ipython/docs/source/whatsnew/version7.rst
Lines 113 to 117 in 73d6335
I thought the event loop is always running. But it's not the case, right?
I was expecting
running=TrueinOut[4].Checked with 73d6335