Le 16/04/2018 à 14:25, Julien Derr a écrit :

thanks very much Martin and François for your answers,

I start to understand a little bit more the various options. But If understand correctlly, it means that under arch linux, If I want to use scikit image, I need a virtual environment ...

To be more precise, you can install either the package provided by the OS (here, from AUR) or wiht pip a virtualenv, not pip as root. My recommandation works for any linux (or even unix) system, not specifically archlinux. (It's just my 2 cents, then you do as you wish ;) ).

Best,