Zope Event

import zope.event

class MyEvent:
    def __init__(self, data):
        self.data = data

def my_subscriber(event):
    print(f"Subscriber 1 received event with data: {event.data}")

def another_subscriber(event):
    print(f"Subscriber 2 processed event: {event.data.upper()}")

# Clear existing subscribers for example isolation (optional for real apps)
# You might not want to do this in production, especially if other parts
# of your application register global subscribers.
_old_subscribers = zope.event.subscribers[:]
del zope.event.subscribers[:]

# Register subscribers
zope.event.subscribers.append(my_subscriber)
zope.event.subscribers.append(another_subscriber)

# Create and notify an event
event = MyEvent("hello world")
zope.event.notify(event)

# Unsubscribe (optional)
zope.event.subscribers.remove(my_subscriber)
zope.event.subscribers.remove(another_subscriber)

# Restore original subscribers (if applicable)
zope.event.subscribers.extend(_old_subscribers)

# Example of notifying with a simple object (any object can be an event)
zope.event.notify(42)
zope.event.notify("a string event")

print("\nDemonstrating direct manipulation of subscribers (for testing/setup):")
# Direct manipulation of the subscribers list is often used in tests
# or initialization, but higher-level frameworks like zope.component
# provide more sophisticated subscription mechanisms.
print(f"Current subscribers: {zope.event.subscribers}")