Hey William, thanks for taking the time to look at my problems
The gis object is created as follows:
I tried the gis.user, but i am pretty sure, that users is correct, because the API Reference lists the create() method as a method of the user-manager class (users) and not the user class. See arcgis.gis module
So from my point of view, the method/syntax is correct, but it does not work....