[lozenge]

That assumes you have a project. Some people write scripts in Python to use in the shell.

[icebraining]

venvs work fine in the shell. See pipsi for automatic creation/management of the necessary venvs.

[eesmith]

Some people write simple programs which they then (say) email to others, or put on a blog post, or on a gist, or a SO answer.

If the simple program depends only on core Python, then they don't also have to say "oh, and also install ...".