Event-Callback system using decorators

events.py

from collections import defaultdict
import functools

events_callbacks = defaultdict(list)


def callback(event_id: str):
    def decorator_callback(func):
        functools.wraps(func)
        events_callbacks[event_id].append(func)
        return func
    return decorator_callback


def run_callbacks(event_id: str, *args):
    for func in events_callbacks[event_id]:
        func(*args)





# Example usage (in another file):
from events import callback
from events import run_callbacks

@callback("user_joined")
def greet_user(name, email):
    send_email(email, f"Welcome, {name}!")

@callback("user_joined")
def db_add_user(name, email):
    add_database_entry(name, email)

def user_signup()
    name  = input("Please insert your name:         ")
    email = input("Please inser your email address: ")

    run_callbacks("user_joined", name, email)