This is lint reported by the new lint-checking functionality in beautify.py.
(We can change to a different lint checker if we have a better one, but it
would probably still flag these same problems.)
Lint checking can help a lot, but only if we get the lint under control.
This is about the last that isn't in contrib or generated files. At this
point we can start doing regular lint checks, at least on the Python files,
without being completely inundated with warnings.
