paul j3 <ajipa...@gmail.com> added the comment:
Parsing is a two step process. First the strings are passed through def _parse_optional(self, arg_string): which classifies them as 'O', an optional flag, or 'A', an argument. - no prefix char => A - the string is in the dictionary of option_strings (e.g. '--list-arg') => O - one char => A - has '=' and first part in option_strings => O - test for abreviations - negative number => O or A - contains space => A - else => unmatched O? (read it for the details) With your inputs, the pattern is: ['--list-arg', 'a', '--text-arg', 'hello world'] O A O? A ['--list-arg', 'a', '--text-arg=hello'] O A O? ['--list-arg', 'a', '--text-arg=hello world'] O A A It's the space in the string marks it as an argument that can be added to the '--list-arg' list. Unmatched optionals go on the 'extras' list. --- In [25]: parser.parse_known_args(['--list-arg', 'a', '--text-arg', 'hello world']) Out[25]: (Namespace(list_arg=['a']), ['--text-arg', 'hello world']) In [26]: parser.parse_known_args(['--list-arg', 'a', '--text-arg=hello']) Out[26]: (Namespace(list_arg=['a']), ['--text-arg=hello']) In [32]: parser.parse_known_args(['--list-arg', 'a', '--text-arg=hello world']) Out[32]: (Namespace(list_arg=['a', '--text-arg=hello world']), []) --- So '--text-arg=hello world' is split into ['--text-arg', 'hello world'] only if '--text-arg' is an option_string. Any ways, the behavior is explainable. Whether the blank should have this priority might be debatable, but I suspect any changes will be rejected on the grounds of backward incompatibility. Your users still have the option of using: --text-arg 'hello world' It may be worth search the issues for an earlier discussion. ---------- nosy: +paul.j3 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue34390> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
