Re: Feedback required - new arguments parsing for rdiff-backup

[Dominic Raferd]

On 02/01/2021 20:38, Eric L. Zolf wrote:
> Hello everybody,
>
> first, let me wish you a happy new year, health and good luck.
>
> I'm currently working on using argparse to improve the way command line
> arguments are parsed, in a way compatible with the old handling while
> developing a new, hopefully more logical and easier to extend, approach.
>
> The attached script is a proof-of-concept, faking the interface and
> printing the result (without any real action), for which I'd like to get
> feedback, especially regarding your daily use of rdiff-backup:
>
> 1. is the compatible interface really similar to the old command line?
> 2. is the output using the old and new interfaces the same? (ignoring
> "null" default values)
> 3. how do you like the new interface? any feedback is welcome.
>
> Few more notes to get you started:
>
> `python3 arguments.py --help` gives you the old interface
> `python3 arguments.py --new --help` gives you the new one
> the new interface makes more clearly the difference between actions
> (backup, restore, compare, etc...) and options, e.g. the old
> `rdiff-backup -b dir1 dir2` becomes `rdiff-backup backup dir1 dir2`.
> A neat trick of the new interface is the ability to create arguments
> files, e.g. restore.txt with one argument per line:
>
> restore
> --at
> 3B
> repository_dir
> target_dir
>
> and use it on the command line with `python3 arguments.py @restore.txt`
>
> I find that filtering away the null values helps to understand the
> output, e.g. with `| grep -v null`.
>
> Hope you like it, let me know in both cases :-)
>
> Thanks, Eric

Thanks Eric for all your great work on rdiff-backup over the last year 
(I now use v2.0.5 on Ubuntu 20.04 and Windows [latter only as client], 
it works great), and all the best for 2021.

But when I try arguments.py I get this:
# python3 --version
Python 3.8.5
# python3 ./arguments.py --help
Traceback (most recent call last):
  File "./arguments.py", line 120, in <module>
    "--fsync", default=True, action=argparse.BooleanOptionalAction,
AttributeError: module 'argparse' has no attribute 'BooleanOptionalAction'