The docstring says "This may be None or an instance of EventLoop". But docs explicitly state that get_event_loop "must never return None". The same docstring is also in the example in docs: https://docs.python.org/3.6/library/asyncio-eventloops.html#customizing-the-event-loop-policy

I propose changing it to:

def get_event_loop(self):
    """Get the event loop.

    Returns an instance of EventLoop or raises an exception.
    """

If the wording is ok, I'll make a PR.

Thanks for the report. This looks like a valid change to me as I can see from the docstring it says it can be None but in the source code there is an explicit check that if self._local._loop which is returned is None then raise a RuntimeError. I would propose removing the docstring in the example.


# Docstring says can be None

./python.exe -m pydoc asyncio.events.BaseDefaultEventLoopPolicy.get_event_loop | cat
Help on function get_event_loop in asyncio.events.BaseDefaultEventLoopPolicy:

asyncio.events.BaseDefaultEventLoopPolicy.get_event_loop = get_event_loop(self)
    Get the event loop.

    This may be None or an instance of EventLoop.


# RuntimeError is raised for None

./python.exe -m inspect asyncio.events:BaseDefaultEventLoopPolicy.get_event_loop
    def get_event_loop(self):
        """Get the event loop.

        This may be None or an instance of EventLoop.
        """
        if (self._local._loop is None and
                not self._local._set_called and
                isinstance(threading.current_thread(), threading._MainThread)):
            self.set_event_loop(self.new_event_loop())

        if self._local._loop is None:
            raise RuntimeError('There is no current event loop in thread %r.'
                               % threading.current_thread().name)

        return self._local._loop

Vlad, the PR is very welcome!

I've fixed the documentation according to the thread.

Here's the PR: GH-16463

Ido

New changeset b23a8423a923077e4f83d3f328bb7542b4c940ed by Yury Selivanov (idomic) in branch 'master':
bpo-34344 Fix AbstractEventLoopPolicy.get_event_loop docstring (GH-16463)
https://github.com/python/cpython/commit/b23a8423a923077e4f83d3f328bb7542b4c940ed

New changeset 8edde5caabc611c6320fd104244abe3a409cf0b6 by Miss Islington (bot) in branch '3.8':
bpo-34344 Fix AbstractEventLoopPolicy.get_event_loop docstring (GH-16463)
https://github.com/python/cpython/commit/8edde5caabc611c6320fd104244abe3a409cf0b6

New changeset 4de3fbe27f672dcd9c24d3e99258f39b12c365a5 by Miss Islington (bot) in branch '3.7':
bpo-34344 Fix AbstractEventLoopPolicy.get_event_loop docstring (GH-16463)
https://github.com/python/cpython/commit/4de3fbe27f672dcd9c24d3e99258f39b12c365a5

New changeset 88204a3908663a574919f9c17278bcabed0598fa by Ned Deily (Miss Islington (bot)) in branch '3.7':
bpo-34344 Fix AbstractEventLoopPolicy.get_event_loop docstring (GH-16463)
https://github.com/python/cpython/commit/88204a3908663a574919f9c17278bcabed0598fa