Django-dated-static is a project mainly written in Python, it's free.
Django templatetag library that adds modification time query params to static files
The purpose of this library is to provide a template tag that can be used to format media files with a timestamp query parameter; the timestamp is based on the last modification time.
::
{% load dated_static %}
<link rel="stylesheet" href="{% dated_static 'css/style.css' %}" type="text/css" media="screen" charset="utf-8"/>::