set_printoptions doesn't return anything.
Simplify chained comparisons.
Don't use mutable default arguments.
Remove duplicate keys from setup metadata.
Remove irrelevant line.
Remove irrelevant line.
Remove unused method arguments.
Move misplaced docstring.
Use triple-double-quotes for docstrings.
Import six from externals.
Fix a stray mutable default argument.
Add missing file-comment-headers.
Merge pull request #342 from enthought/feature/static-analysis

Fix miscellaneous things uncovered by static analysis