paul j3 <ajipa...@gmail.com> added the comment:
Xiang Zhang pointed out that the immediate error in this case was caused by the empty mutually exclusive group: https://bugs.python.org/issue26952#msg264835 The nesting fails because adding actions to the argument_group does not enroll them in the mutually exclusive group. So the group._group_actions list remains empty, just as it is in your case. As I pointed out earlier, the usage formatter is brittle. The addition of mutually exclusive group markings is particularly clunky. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue26952> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com