This one's incorrect.  The "if not value" is part of a continuation line so it needs some indent.  Because we're doing this looping for the side effect rather than the return value, the single space indent isn't enough of a visual cue.  I think that pep8 allows varying amounts of indent -- http://www.python.org/dev/peps/pep-0008/#indentation has an example that says "Optional: 
# Extra indentation is not necessary."

So for me you could leave this as an 8-space indent or change it to a 4-space indent.

(Note -- on f20, /usr/bin/pep8 doesn't seem to complain with a 4-space indent so that might be what you want to use.)