[Distutils] disable register and upload commands for a setup.py

[Jeff Kowalczyk]

What would be the most reliable way to disable, with error output, the
PyPI 'register' and/or 'upload' commands for a given setup.py?

This is for developing certain python egg/packages having setup.py:setup()
including full package metadata, but which should never (or not yet)
accidentally be registered with PyPI.

Thanks.