Deprecated coroutine

[albireox]

Versions

• Python: 3.8
• OS: macOS 10.15
• Pymodbus: 2.3.0
• Modbus Hardware (if used): WAGO

Pymodbus Specific

• Client: tcp - async

Description

Trying to import from pymodbus.client.asynchronous.asyncio import AsyncioModbusTcpClient produces a series of messages [WARNING]: "@coroutine" decorator is deprecated since Python 3.8, use "async def" instead (DeprecationWarning). Python 3.8 has deprecated the coroutine decorator. Also, there is a filter in pymodbus that always shows these warnings so it's not possible to suppress them.

[JamesJeffryes]

@dhoomakethu I'm happy to open a PR to address this. One thing to note is that converting to use of the async keyword would limit the library to 3.5+ but that seems like a pretty reasonable limitation to me.

[dhoomakethu]

Yes, pymodbus 3 would be only available for Python 3.5 and above and it should be good to have that change. Feel free to raise a PR

[swamper123]

This was cleaned up with #564 .
At least I couldn't find any decorator.