Python 3.8 warnings

[adamchainz]

I'm seeing this warning on Python 3.8:

/.../lib/python3.8/site-packages/ocpp/charge_point.py:184: DeprecationWarning: "@coroutine" decorator is deprecated since Python 3.8, use "async def" instead
  response = await asyncio.coroutine(handler)(**snake_case_payload)

Is there any reason not to convert the associated methods to async def ?

[OrangeTux]

Thanks for the report. This line executes the handlers that are registered for an action. Handlers can be both regular functions as well as async functions. E.g.:

@on("Heartbeat")
def on_heart_beat(*args, **kwargs):
    pass

@on("Heartbeat")
async def on_heart_beat(*args, **kwargs):
    pass

response = await asyncio.coroutine(handler)(**snake_case_payload) makes sure that that both version can be executed.
You state correctly that asyncio.coroutine is depricated. Therefore I think we should replace it with:

response = handler(**snake_case_payload)
if inspect.isawaitable(response):
                 response = await response

[laysauchoa]

cc @OrangeTux
Hey, is someone working on this ticket?

[OrangeTux]

Nope.