Those APIs are used by pickle and provide a great way to handle escaped bytes sequences in much the same way as str (bytes)/repr (bytes) works. In Python 2, these were used by the string_escape codec, ...

I have an app that worked fine on python 2.7. I needed to upgrade to python 3.4 and the speech to text stopped to work. Yes, I ported to my code to python 3 and everything but speech to text works ...