This is an example of a Decorator Factory in python, used in the youtube short: https://www.youtube.com/watch?v=H_0vd0h1_b8&lc=Ugw3j1mHk4fWXCU_0Sp4AaABAg

DecoratorFactory.py

from datetime import datetime


def new_event(functions: dict, event: str):
    def func(callback):
        def wrapper(self):
            return callback(self)

        functions[event] = wrapper
        return callback

    return func


class StopWatch:
    def __init__(self):
        self.start_time = None
        self.end_time = None
        self.running = False

    def start(self):
        if not self.running:
            self.start_time = datetime.now()
            self.running = True
            return True
        return False

    def stop(self):
        if self.running:
            self.end_time = datetime.now()
            self.running = False
            return True
        return False


    def get_time(self):
        if not self.start_time:
            return False
        if self.running:
            return datetime.now() - self.start_time
        else:
            return self.end_time - self.start_time


class InputHandler:
    functions = {}

    def __init__(self):
        self.stop_watch = StopWatch()

    def __call__(self, command: str):
        if command in self.functions:
            self.functions[command](self)
        else:
            print(f"Unknown command: {command}")

    @new_event(functions, "start")
    def start(self):
        if self.stop_watch.start():
            print("Stopwatch started")
        else:
            print("Stopwatch already running")

    @new_event(functions, "stop")
    def stop(self):
        if self.stop_watch.stop():
            print(f"Elapsed time: {self.stop_watch.get_time()}")
        else:
            print("Stopwatch not running")

    @new_event(functions, "get_time")
    def get_time(self):
        if self.stop_watch.get_time():
            print(f"Elapsed time: {self.stop_watch.get_time()}")
        else:
            print("Stopwatch not running")


if __name__ == "__main__":
    input_handler = InputHandler()
    while True:
        command = input("Enter a command: ")
        input_handler(command)