I use python professionally and can't make sense of this comment. I'm doing my thing, running my ls, cd, greps and cats, and now I need to run my python cli.... And so I do pip install in which env exactly? The system one? Or do I have to create a venv just to install my python cli, and have to enable it every time I wanna run the cli? It's easy to say "just pip install", but I can't see how the details make sense in the context of a cli. Explain please?