check if function is async in python 3.7

Question

I'd like to check if a function is async before calling it in python. For example, here I'd like to check if f is async so that await makes sense:

async def call_async_f(f):
    assert function_is_async(f)
    await f()

How could I implement function_is_async? I'm using python 3.7 which seems to have some interesting new async features and I don't mind a 3.7-specific solution.

A function doesn't have to be defined as `async` for the return value to be awaitable. — user2357112, Jan 29 '19 at 18:45
That's a bad idea because the `f` could be a sync function that returns an awaitable (a `Future`, a coroutine objects, etc.), just like an iterable can be of many different types... — user4815162342, Jan 29 '19 at 19:08

score 3 · Answer 1 · answered May 21 '19 at 14:31

3

inspect has checks for most types of async objects, in your case it`s iscoroutinefunction

import inspect
async def call_async_f(f):
    assert inspect.iscoroutinefunction(f)
    await f()

answered May 21 '19 at 14:31

Trizalio

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check if function is async in python 3.7

1 Answers1