STINNER Victor <vstinner@redhat.com> added the comment: I have no opinion on the change in the master branch, but I agree with Christian that the 3.7 change should be reverted since it breaks the backward compatibility. Serhiy modified int() in Python 3.7 to convert its first parameter to positional only parameter. IMHO it's ok to do such change. Moreover, the change has been documented in What's New in Python 3.7: https://docs.python.org/dev/whatsnew/3.7.html#api-and-feature-removals If you decide to keep the change in the master branch, it should be documented in What's New in Python 3.8, no? ---------- _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33729> _______________________________________