My 'Event Dispatcher' implementation in python.

EventDispatcherExample.py

class EventDispatcher:
    def __init__(self):
        self.__eventhandlers = {}

    def add_event(self, event, handler):
        self.__eventhandlers[event] = handler

    def remove_event(self, event):
        del self.__eventhandlers[event]

    def call_event(self, event, *args, **kwargs):
        self.__eventhandlers[event](*args, **kwargs)

class MainClass:
    def __init__(self):
        self.secondary = SecondaryClass()
        self.event_dispatcher = self.secondary.get_event_dispatcher()
        self.event_dispatcher.add_event("show_text", self.show_text)
        
    def show_text(self, text):
        print(text)

    def trigger(self):
        self.secondary.simulate_event()

class SecondaryClass:
    def __init__(self):
        self.on_event = EventDispatcher()

    def get_event_dispatcher(self):
        return self.on_event

    def simulate_event(self):
        self.on_event.call_event("show_text", "some text")

main = MainClass()
main.trigger()