Events

Bringing the elegance of C# EventHandler to Python

events Permissive license BSD Abandoned ★ 329 v0.5 released 2023-07-31

Install

events on PyPI

pip

pip install events

uv

uv add events

poetry

poetry add events

Package facts

License	BSD (permissive)
Python support	not specified
Install friction	low — pure-Python wheel
Runtime dependencies	none
Maintenance	abandoned — 1,109 days since the last release
Last repo commit	2023-08-07
First released	2013-03-13
Popularity	one of the top 1,000 most-downloaded packages on PyPI (30-day window, as of 2026-08-13)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-13)

Evidence: Events-0.5-py3-none-any.whl

Development Status :: 4 - BetaIntended Audience :: DevelopersLicense :: OSI Approved :: BSD LicenseOperating System :: OS IndependentProgramming Language :: PythonProgramming Language :: Python :: 2Programming Language :: Python :: 2.7Programming Language :: Python :: 3Programming Language :: Python :: 3.4Programming Language :: Python :: 3.5Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Topic :: Software Development

About Events

from the package's own PyPI description — quoted content, verbatim

Events

The C# language provides a handy way to declare, subscribe to and fire events. Technically, an event is a "slot" where callback functions (event handlers) can be attached to - a process referred to as subscribing to an event. Here is a handy package that encapsulates the core to event subscription and event firing and feels like a "natural" part of the language.

&gt;&gt;&gt; def something_changed(reason): 
...     print "something changed because %s" % reason

&gt;&gt;&gt; from events import Events
&gt;&gt;&gt; events = Events()
&gt;&gt;&gt; events.on_change += something_changed

Multiple callback functions can subscribe to the same event. When the event is fired, all attached event handlers are invoked in sequence. To fire the event, perform a call on the slot:

&gt;&gt;&gt; events.on_change('it had to happen')
'something changed because it had to happen'

By default, Events does not check if an event can be subscribed to and fired. You can predefine events by subclassing Events and listing them. Attempts to subscribe to or fire an undefined event will raise an EventsException.

&gt;&gt;&gt; class MyEvents(Events):
...     __events__ = ('on_this', 'on_that', )...

Read as markdown · JSON record · Source repository · Homepage

AI interpretation — verify before relying

AI-generated interpretation of the package facts above; every digit, version, license, or vulnerability id it cites is grounded in the facts already shown on this page

Events provides a publish-subscribe pattern for Python, letting you attach callback functions to named events and fire them to notify all subscribers—similar to C# event handlers.

Installation is frictionless with low friction and no runtime dependencies, but the package has been abandoned since its last release on 2023-07-31, with no maintenance activity.

BSD license permits commercial and private use with minimal restrictions, requiring only license and copyright notice retention.

Usage

pip install events

from events import Events

events = Events()
events.on_change += lambda reason: print(f'Changed: {reason}')
events.on_change('test')

Verdict: Events is a lightweight, dependency-free event dispatcher suitable for simple pub-sub patterns, but its abandoned status and Beta development classification mean it carries maintenance risk. No known vulnerabilities exist, and the permissive BSD license poses no legal barrier.

Needs verification

Whether the package remains compatible with Python 3.9+ despite classifiers only listing up to 3.8
Whether memory leaks from held references (mentioned in docs) have been addressed or remain a known issue
Current community adoption and whether alternatives have superseded this package

event emitter pythonpublish subscribe callbacksevent handler patternobserver pattern implementationsignal dispatchevent listener frameworkcallback subscription system