yeah. not necessary -- if you've got your editor properly configured for python whitespace.
many editors (in addition to vim, emacs.. like textmate, sublime, etc) will honor these old-school vim mode lines.

might be worth linking to a dev environment configuration guide so people can figure out how to set up their editor for python (esp so we avoid mixed tabs and spaces) http://docs.python-guide.org/en/latest/dev/env.html

probably couldnt hurt to link to a general python style guide too: http://docs.python-guide.org/en/latest/writing/style.html