Downside is, ofc, that compared to just running something inside a virtualenv shell, vpython takes forever (up to 100ms-ish on my machine) to find the virtualen

Downside is, ofc, that compared to just running something inside a virtualenv shell, vpython takes forever (up to 100ms-ish on my machine) to find the virtualenv, and set the correct env variables. Most of my projects are long running though (webservers, number crunchers, etc), so the extra miliseconds it takes to load is really not that important.