Using classes and inheritance cause problems with lingering triggers

[carlolars]

So I tried to be clever and structure my code into classes. It works, kind of.
My use case is I have a few ZigBee devices of the same type in different rooms for which I wait for events and then do stuff.

I created a base class for the zha event, then classes for different devices that inherit from the base class, and then I created instanses of the classes in several script files (pyscript/scripts/).

The base class creates a list of triggers that is attached to self, so I expected those triggers to be destroyed when the reference to the class instance is lost, ie when reloading the script that creates the class instance and has the reference to it.
But that is not happening, instead every time I reload the script it just adds more triggers without destroying the previous ones. I have to reload the file that contains the definition of the base class for the triggers to be destroyed.

But if I don't have a reference to the instance (remove ws_hallway below) then nothing happens when I push the switch which I assume is because the triggers have been destroyed when the instance was not referenced anymore.

What am I missing here?

---

This is basically how I implemented it:

pyscript/modules/zha.py:

class ZhaEventBase:
    def __init__(self):
        # Cannot use `super().__init__()` so use `zha_event_base()` instead
        pass

    def zha_event_base(self,
                 device_id:str,
                 command_callbacks:dict):
        """
        `command_callbacks` is a flat dictonary with `"command": callback`.
        """
        self.triggers = []

        for command, callback in command_callbacks.items():
            if callback is not None:
                log.debug(f"Registering command '{command}'")
                @event_trigger("zha_event", f"device_id == '{device_id}' and command == '{command}'")
                def zha_event_callback(device_id=None, command=None, args=None, **kwargs):
                    callback(device_id, command, args)

                self.triggers.append(zha_event_callback)

pyscript/modules/philips_hue.py:

from zha import ZhaEventBase

class WallSwitch(ZhaEventBase):
    def __init__(self,
        device_id:str,
        command_callbacks:dict):
        self.zha_event_base(device_id, command_callbacks, debug)

pyscript/scripts/hallway.py:

from philips_hue import WallSwitch

def wall_switch_toggle(device_id, command, args):
    log.debug(f"wall_switch_toggle, {command=}")

ws_hallway = WallSwitch("123456778888888888",
           {
            "left_press_release": wall_switch_toggle,
           })