[$] Python 3.9 is around the corner

. Python 3.9
will come with new operators for dictionary unions, a new parser, two string
operations meant to eliminate some longstanding confusion, as well as
improved time-zone handling and type hinting. Developers may need to do some
porting for code coming from Python 3.8 or earlier, as the new release has
removed several previously-deprecated features still lingering from Python
2.7.