bpo-27485: Rename and deprecate undocumented functions in urllib.parse by csabella · Pull Request #2205 · python/cpython
The following functions were undocumented:
splitattr, splithost, splitnport, splitpasswd, splitport, splitquery, splittag, splittype, splituser, splitvalue, to_bytes, unwrap
A note in the 2.7 documentation for urllib stated that Python 3 does not expose these helper functions, but yet they were still available.