argparse

How can I add an argument that is optional and must not be specified multiple times? Valid: $ ./my.py $ ./my.py --arg MyArgValue Invalid: $ ./my.py --arg MyArgValue --arg ThisIsNotValid If I add an argument like: parser.add_argument('--arg', type=str) The invalid example results in a string ThisIsNotValid . I would expect a parser error. Create a custom action that raises an exception if the same argument is seen twice. When the parser catches the exception, it prints the usage and a nicely-formatted error message. import argparse class Highlander(argparse.Action): def __call__(self, parser,

Hi colleagues I have the code (max_help_position is 2000): formatter_class=lambda prog: argparse.HelpFormatter(prog, max_help_position=2000) parser = argparse.ArgumentParser(formatter_class=formatter_class) subparsers = parser.add_subparsers(title="Commands", metavar="<command>") cmd_parser = subparsers.add_parser('long_long_long_long_long_long_long', help='- jksljdalkjda', formatter_class=formatter_class) args = parser.parse_args(['-h']) print args we have optional arguments: -h, --help show this help message and exit Commands: <command> long_long_long_long_long_long_long - jksljdalkjda small

I know that does not make sense multiple positional arguments into a mutually exclusive group because you can't say who is who. But I need to include ONE positional argument into that. What I need: $ myprogram -h usage: myprogram [-h] [--delete value | --update value | value] Where positional value is the default action (kind of "--include"). ( myprogram without arguments must be valid too). My first attempt (this doesn't works): parser = ArgumentParser() group = parser.add_mutually_exclusive_group() group.add_argument('--delete', metavar='value') group.add_argument('--update', metavar='value'

This question already has answers here : Closed 3 years ago . Simple argparse example wanted: 1 argument, 3 results (10 answers) I want to send arguments to script by their name (something like kwargs). I tried something like this but it's not doing what I want: (let's say it's written in script.py) import argparse parser = argparse.ArgumentParser() parser.add_argument("name") args = parser.parse_args() and then writing in commant line: script.py name = david another thing, let's say I have few named argument in argparse If I will send them not in the order they are declared will it still work

what I'd like to do in Python is accept arguments of the following format: script.py START | STOP | STATUS | MOVEABS <x> <y> | MOVEREL <x> <y> So in other words, I don't want to deal with hyphens; I have multiple possibilities, ONE of which is required; Each is mutually exclusive; Some of the commands (E.G. moveabs and moverel) have additional required arguments, but these args and should not be present with any other argument. Can this be done in python and would I use argparse or something else? Thanks. hpaulj add_parser with subparsers would do the trick import argparse parser = argparse

Is there a way to write a python doctest string to test a script intended to be launched from the command line (terminal) that doesn't pollute the documentation examples with os.popen calls? #!/usr/bin/env python # filename: add """ Example: >>> import os >>> os.popen('add -n 1 2').read().strip() '3' """ if __name__ == '__main__': from argparse import ArgumentParser p = ArgumentParser(description=__doc__.strip()) p.add_argument('-n',type = int, nargs = 2, default = 0,help = 'Numbers to add.') p.add_argument('--test',action = 'store_true',help = 'Test script.') a = p.parse_args() if a.test: