Serhiy Storchaka <storchaka+cpython@gmail.com> added the comment: Actually removing re._pattern_type, uuid._uuid_generate_time and some private names in the typing module broke several third-party projects. See for example: https://github.com/search?q=_pattern_type&type=Issues https://github.com/search?q=_uuid_generate_time&type=Issues https://github.com/bintoro/overloading.py/issues/5 https://github.com/hsolbrig/PyShEx/issues/17 I'm sure there are examples for other removed names. I don't understand why os.errno should be special. Books can contain errors (e.g. the claim that Python 3 is not Turing complete). ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33666> _______________________________________