Alexander Kapshuna <ka...@kap.sh> added the comment:
I have a feeling that nesting groups has nothing to do with it. Got same traceback when I forgot to fill my mutually exclusive groups with arguments. import argparse parser = argparse.ArgumentParser() group = parser.add_mutually_exclusive_group() parser.parse_args(['-h']) # Result: Traceback (most recent call last): File "/home/kapsh/.PyCharmCE2019.1/config/scratches/scratch_12.py", line 5, in <module> parser.parse_args(['-h']) File "/usr/lib/python3.7/argparse.py", line 1749, in parse_args args, argv = self.parse_known_args(args, namespace) File "/usr/lib/python3.7/argparse.py", line 1781, in parse_known_args namespace, args = self._parse_known_args(args, namespace) File "/usr/lib/python3.7/argparse.py", line 1987, in _parse_known_args start_index = consume_optional(start_index) File "/usr/lib/python3.7/argparse.py", line 1927, in consume_optional take_action(action, args, option_string) File "/usr/lib/python3.7/argparse.py", line 1855, in take_action action(self, namespace, argument_values, option_string) File "/usr/lib/python3.7/argparse.py", line 1037, in __call__ parser.print_help() File "/usr/lib/python3.7/argparse.py", line 2474, in print_help self._print_message(self.format_help(), file) File "/usr/lib/python3.7/argparse.py", line 2458, in format_help return formatter.format_help() File "/usr/lib/python3.7/argparse.py", line 284, in format_help help = self._root_section.format_help() File "/usr/lib/python3.7/argparse.py", line 215, in format_help item_help = join([func(*args) for func, args in self.items]) File "/usr/lib/python3.7/argparse.py", line 215, in <listcomp> item_help = join([func(*args) for func, args in self.items]) File "/usr/lib/python3.7/argparse.py", line 322, in _format_usage action_usage = format(optionals + positionals, groups) File "/usr/lib/python3.7/argparse.py", line 397, in _format_actions_usage start = actions.index(group._group_actions[0]) IndexError: list index out of range ---------- nosy: +kapsh _______________________________________ 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