I think you are missing the point.  I quoted the line from PEP8 that specifically states "use your own judgement".  It is impossible to strictly follow the PEP8 document without exercising judgement, i.e. there is no definite right or wrong answer here.

The coding guidelines state that I should follow PEP8.  I have.  If you think the coding guidelines should be changed to follow pep8 (the tool, not the document) then you should start such a discussion on the matplotlib-devel mailing list.