Things have changed; I have a new laptop and the Pywikipedia framework is now developed using GIT. There is documentation but it deserves an update. It seemed for instance that there are four things to install but actually there are three. I do not know why there is something about a "clone".
The good news is that at the pywikipedia IRC channel there are people quite happy to help. You have to start for instance in the folder with the "core" software and, this is where the user-config.py has to be as well. And, make sure that you have all the quotes at the right places. How did you copy and past again from a terminal session ... I am grateful for their patience.
I ended up with the following command:
python pwb.py harvest_template.py "-cat:Presidents of Uruguay" "-template:Infobox Officeholder" -namespace=0 p102 party
It did exactly nothing and I have no clue why. I saw all the president of Uruguay being processed and I know it is in the template and, p102 is the party...
Please help because Wikidata needs more data.