---
layout: default
navsection: sdk
navmenu: Python
title: Subscribing to database events
...
{% comment %}
Copyright (C) The Arvados Authors. All rights reserved.

SPDX-License-Identifier: CC-BY-SA-3.0
{% endcomment %}

Arvados applications can subscribe to a live event stream from the database.  Events are described in the "Log resource.":{{site.baseurl}}/api/methods/logs.html

{% codeblock as python %}
#!/usr/bin/env python3

import arvados
import arvados.events

# 'ev' is a dict containing the log table record describing the change.
def on_message(ev):
    if ev.get("event_type") == "create" and ev.get("object_kind") == "arvados#collection":
        print "A new collection was created: %s" % ev["object_uuid"]

api = arvados.api("v1")
ws = arvados.events.subscribe(api, [], on_message)
ws.run_forever()
{% endcodeblock %}