pypa/pipx ? reverse-engineered prompt

Build me a Python command line tool like pipx that makes it easy to install and run Python apps in isolated environments.

I want it to let me install a package that has a command line entry point, run it in its own clean virtual environment, and manage those installs afterwards. So I should be able to install something like a small CLI app, list what I have, upgrade it, uninstall it, and also run the latest version of a package once without keeping it around. It should work with normal user permissions, not require sudo, and avoid dependency conflicts between different apps.

Please make it feel polished and practical, with good help text, sensible defaults, and clear error messages. If you need to check current Python packaging docs or behavior, look up the latest info online. Also include tests and basic documentation so it’s easy to understand how to use it.