[Python-Dev] iscoroutinefunction vs. coroutines

9 Mar 2017

      Hi,

Is this pattern

	def foo():
		return bar()
	async def bar():
		await <whatever>

	async def async_main():
		await foo()

considered to be valid?

The reason I'm asking is that some code out there likes to accept a
might-be-a-coroutine-function argument, using

	def run_callback(fn):
		if iscoroutinefunction(fn):
			res = await fn()
		else:
			res = fn()

instead of

	def run_callback(fn):
		res = fn()
		if iscoroutine(res):
			res = await res()

The former obviously breaks when somebody combines these idioms and calls

	run_callback(foo)

but I can't help but wonder whether the latter use might be deprecated, or
even warned about, in the future and/or with non-CPython implementations.

-- 
-- Matthias Urlichs