[Python-ideas] Type hints for text/binary data in Python 2+3 code

[Guido van Rossum]

One thing I can do without committing to too much is to add a Text
type to typing.py. It would have no (defined) behavior but it could be
imported and used in annotations. Then mypy and other checkers could
start using it and we could even experiment with different proposals
without having to make more changes to typing.py (which we've found
are hard to push out, because it's in the 3.5 stdlib -- it's
provisional so we can change it, but we can't easily change what's
already in 3.5.0 or 3.5.1).

Should it be possible to subclass Text, and what should it mean?

Or perhaps at runtime (i.e. in typing.py) Text would just be an alias
for str in Python 3 and an alias for unicode in Python 2? That's
easiest.