[xwiki-users] Python macro scripting - available packages?

Hi, I'm trying to import some packages into the Python macro on Xwiki 7.2, and while standard packages import fine (working with os and re, etc.), some (like xlrd) don't. Looking through the scripting guide and macro documentation I could not figure out how the Python macro actually works. Is it just a collection of bindings and translates the python script into groovy or something else, or is it calling the local Python installation? This might sound stupid, but I thought the latter was the case and this would limit the available packages (the ones I want to load are installed locally). Thank you Sebastian