That's quite surprising to me too, BTW. I was focused on generator vs `async def ...` coros and hadn't even tried the legacy decorator.
Would it be possible for asyncio code to be altered in a way that produces awaitables which conform with inspect's protocol? Ie. through code flags or some other flag that inspect looks for? I assume a similar stance could then be taken by other async libraries. If it's just not in the cards may I humbly suggest the docs for the inspect module include some language to help users avoid some of these idiosyncrasies? Justin On Mon, Nov 7, 2016 at 10:20 PM Yury Selivanov <yseliva...@gmail.com> wrote: > Introspection functions from the inspect module are designed for native > types. Introspection functions from asyncio are designed for what asyncio > treats as coroutines. Consider this example: > > @asyncio.coroutine > def coro(): > print(‘hello’) > > ‘asyncio.iscoroutinefunction' will return ‘True' for ‘coro’, because it > knows how specifically asyncio wraps non-generator functions. To make > ‘inspect.iscoroutinefunction’ recognize ‘coro’ as a coroutine function we > would need to make ‘inspect’ aware of asyncio. But asyncio is just one > user of async/await and generator-based coroutines. Twisted and Tornado > have their own coroutine decorators, we can’t make inspect to recognize > coroutines from them all. > > Yury > > > > > On Nov 8, 2016, at 12:03 AM, Justin Mayfield <too...@gmail.com> wrote: > > > > I know this is documented in PEP 492 but I'm struggling to understand > why the inspect module has several test functions (iscoroutine, > iscoroutinefunction, isawaitable) that only work for native coros. > Comparatively the same functions in the asyncio module work for both native > and generator based coros. > > > > It was an interesting exercise for me to figure this out the hard way so > it's safe to say there is peril in this distinction for at least one > developer. Furthermore, the docs for both sets of functions don't elude to > these subtle but important distinctions. > > > > Are there good reasons for this distinction going forward? > > > > Here are some surprising (to me) tests... > > > > Python 3.5.2 (default, Oct 14 2016, 12:54:53) > > [GCC 6.2.1 20160916 (Red Hat 6.2.1-2)] on linux > > Type "help", "copyright", "credits" or "license" for more information. > > >>> import inspect > > >>> import asyncio > > >>> inspect.iscoroutinefunction(asyncio.sleep) > > False > > >>> asyncio.iscoroutinefunction(asyncio.sleep) > > True > > >>> inspect.iscoroutine(asyncio.sleep(1)) > > False > > >>> asyncio.iscoroutine(asyncio.sleep(1)) > > True > > >>> inspect.isawaitable(asyncio.sleep(1)) > > 256 > > > > > > The last test is particularly interesting; At least it's truthy? > > > >
