You can also set a PYTHONUSERBASE environment variable (and `pip install --user`) to scope the installed packages to the project's directory. This is effectively the same as a virtualenv, but doesn't have the requirement on bash or "activation", and it's less magical than virtualenv because these choices are explicit on each command. The tradeoff is that it can be tedious to be explicit, remembering to use `--user` and specify the PYTHONUSERBASE. If you're scripting everything via make, though, then that's not such a burden.