In edit 1.921 of wikipedia.py, it was tried to avoid some edit conflicts. Unfortunately, this was done by always claiming we had seen the last version of the page, and thus throwing away the intermediate edits. This version and subsequent versions of wikipedia.py will revert the other party's edits in case of an edit conflict!!!!
Because of this, everyone who currently has version 1.921 to 1.926 of wikipedia.py is very strongly advised to stop any bots (at least if it will be saving pages) and first download wikipedia.py 1.927 (or newer) and family.py 1.248 (or newer) before restarting them (the latter is necessary because it contains an extension that this newest version of wikipedia.py uses).