@tomasino (my two cents from not real developer)
imho in web or/and scientific context virtualenv just good enough. usually its server or environment (jango, or ipython/jupyther) and if you need another server you just reinstall all required libs via pip, like apt in debian. so it's more os or shell, than application.
but software development on python is terra incognita for me, so so I'll watch for other answers too :)
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko