How to understand the `::` in the python config file?

From the github address:

https://github.com/openstack/nova/blob/master/setup.cfg

In the setup.cfg, there is code below:

[metadata]
name = nova
summary = Cloud computing fabric controller
description-file =
    README.rst
author = OpenStack
author-email = openstack-dev@lists.openstack.org
home-page = http://docs.openstack.org/developer/nova/
classifier =
    Environment :: OpenStack
    Intended Audience :: Information Technology
    Intended Audience :: System Administrators
    License :: OSI Approved :: Apache Software License
    Operating System :: POSIX :: Linux
    Programming Language :: Python
    Programming Language :: Python :: 2
    Programming Language :: Python :: 2.7

The contents in the [] means config name. such as name means key, the below means value.

but how about the Environment :: OpenStack, does the :: have practical meaning?

Solution

No, the :: has no special meaning other that that's the picked delimiter for Trover classifier levels.

The classifiers are just metadata, helping people find specific packages and learn what the package is about. The package maintainer picks these when writing the setup.py script; the setup.cfg file is an alternative way of specifying the same.