New submission from BJ Dierkes: Related: http://bugs.python.org/issue9253
I came across issue9253 in trying to implement a default action for a subparser namespace. In the absence of a 'default' option, I thought that it may be possible by adding an 'action' to 'add_subparsers'. Per the documentation this should be possible: https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.add_subparsers [QUOTE] action - the basic type of action to be taken when this argument is encountered at the command line [/QUOTE] That said, custom actions on 'add_subparsers' doesn't appear to work at all: import argparse class CustomAction(argparse.Action): def __call__(self, parser, namespace, values, option_string=None): print('Inside CustomAction') setattr(namespace, self.dest, values) root_parser = argparse.ArgumentParser(prog='myapp') sub_parser = root_parser.add_subparsers(dest='commands', action=CustomAction) args = root_parser.parse_args() Produces: $ python argtest.py --help Traceback (most recent call last): File "argtest.py", line 46, in <module> sub_parser = root_parser.add_subparsers(dest='commands', action=CustomAction) File "/usr/local/Cellar/python/2.7.3/Frameworks/Python.framework/Versions/2.7/lib/python2.7/argparse.py", line 1661, in add_subparsers action = parsers_class(option_strings=[], **kwargs) TypeError: __init__() got an unexpected keyword argument 'prog' Erroneous documentation maybe? Tested the same on Python 2.7 and 3.3. ---------- components: Library (Lib) messages: 236254 nosy: derks priority: normal severity: normal status: open title: argparse: add_subparsers 'action' broken type: behavior versions: Python 2.7, Python 3.3 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23487> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
