Whistle - Event Dispatcher

Whistle is a lightweight Python library for decoupled application communication through event dispatching and listening. It enables components to interact without direct dependencies, making your code more modular, testable, and maintainable.

from whistle import EventDispatcher

dispatcher = EventDispatcher()

@dispatcher.listen("user.registered")
def send_welcome_email(event):
    print(f"Welcome, {event.username}!")

dispatcher.dispatch("user.registered")

Features

  • Synchronous and asynchronous dispatching - Choose the right dispatcher for your use case

  • Priority-based listener execution - Control the order listeners run

  • Event propagation control - Stop event flow when needed

  • Type safety - Prevent mixing sync and async listeners

  • Custom events - Attach domain-specific data to events

  • Zero dependencies - Lightweight and easy to integrate

Learning Path

Follow this guide to learn Whistle from basics to advanced usage:

Getting Started

Core Features

Advanced Usage

Reference