Some easy things to do now that we're on py3 (well, technically not quite yet, give it a couple hours/days :P):

• Run the noop_u fixer from our 2to3 fork - replaces u'' r'*' -> r'*'
• Slowly uproot OrderedDicts ( 74827fa...4f418ed f628c21)
• Run the object_super fixer from our 2to3 fork - removes all (object) superclasses which are superfluous on py3 (e.g. class Foo(object): -> class Foo:)
• (more tricky) Use super().meth() instead of super(SelfClass, self).meth() - this will make the uses that use parents higher on the mro stand out
• Progressively revisit regexes -> re.U is not needed -> https://docs.python.org/3/library/re.html#re.A - usually the code around needs dusting (or the regx to go altogether see 0f10a43 for reOblivion for instance) so don't just search/replace en masse

Things we may also want to consider:

• Run the unicode_literals fixer from our 2to3 fork - gets rid of all u'' prefixes (e.g. u'this is a string -> 'this is a string')