Without commenting on this specific proposal, I would like to make an overall observation that Python is impairing its usability by adding too-many-ways-to-it in a number of categories (file descriptor variants of file methods, multiple versions of time.time, byte variants of everything that is done with strings).  Python 3 was intended to be a cleaner, more learnable version of Python.  Instead, it is growing enums, multiple dispatch, and multiple variants of every function.   Professional programmers can be well served by some of the these tools, but the Python universe is much larger than that and the other users are not being well served by these additions (too many choices impairs usability and learnability).