add in extra message to tell the user how to get help when trying to use the CLI

[mschwamb]

Fixes #1019

This PR If a user is new to linux/unix they might not be sure what to do to get the detailed help content from the CLI adds in SorchaArgumentParser class a subclass of the argparse.ArgumentParser that adds in an extra message to tell the user to do a sorcha verb -h .

I also modified the prog keyword so that it reflects the CLI commands since the user won't use sorcha-run they will be typing sorcha run (for example)

Review Checklist for Source Code Changes

• [X] Does pip install still work?
• [X] Have you written a unit test for any new functions?
• [X] Do all the units tests run successfully?
• [X] Does Sorcha run successfully on a test set of input files/databases?
• [X] Have you used black on the files you have updated to confirm python programming style guide enforcement?

[mschwamb]

Since I'm mucking with the CLI @mjuric can you take a look? Should take you 2 minutes. Some people using the CLI thought it wasn't clear what to do if you ran sorcha-run with no arguments. So I added an extra message to STDERR if there's no user provided arguments.

[mschwamb]

I even know what you're talking about. So maybe I did learn something python class stuff. I agree, your way is more elegant. I was thinking we didn't need to do this for all the times that someone screwed up the arguments, but I see your way is classier. I'll see where I get to and request a review when I've implemented this. Though it's gonna take me a bit to look at the python class tutorials again for me to do this/ double check what you've written will work (it probably will)

[mjuric]

FWIW, your current solution is also OK, if you want to quickly merge this PR & move the generalization to "future enhancements".

I'd offer to implement this myself but I'm underwater with return travel & other things for a few more days :(.

[mschwamb]

Nah. This is good for my soul. I'm back to having some energy, so I'm gonna try to get to this tonight/this week. I need to do something useful rather than emails, telecons, and commenting on paper drafts. So this is a good small task for me.

[mschwamb]

I did some reading implemented this and I'm getting this behavior that works but the output is a bit odd:

usage: ArgumentParser(prog='sorcha-run', usage=None, description='Run a simulation.', formatter_class=<class 'argparse.ArgumentDefaultsHelpFormatter'>, conflict_handler='error', add_help=True) [-h] -c C -o O -ob OB -p P -pd PD [-er ER] [-ew EW] [-ar AR] [-cp CP] [-f] [-s S] [-t T] [-v] [-st ST] For more detailed help, use the -h flag ArgumentParser(prog='sorcha-run', usage=None, description='Run a simulation.', formatter_class=<class 'argparse.ArgumentDefaultsHelpFormatter'>, conflict_handler='error', add_help=True): error: the following arguments are required: -c/--config, -o/--outfile, -ob/--orbit, -p/--params, -pd/--pointing_database Error: Command 'sorcha-run' failed with exit code 2.

instead of

usage: sorcha-run [-h] -c C -o O -ob OB -p P -pd PD [-er ER] [-ew EW] [-ar AR] [-cp CP] [-f] [-s S] [-t T] [-v] [-st ST] For more detailed help, use the -h flag sorcha-run: error: the following arguments are required: -c/--config, -o/--outfile, -ob/--orbit, -p/--params, -pd/--pointing_database Error: Command 'sorcha-run' failed with exit code 2.

I implemented

class sargparse(argparse.ArgumentParser):
    def __init__(self, *argv, **kwargs):
       super().__init__(*argv, **kwargs)

    def print_usage(self,file=None):
        super().print_usage(file)
        print("For more detailed help, use the -h flag",file=sys.stderr)

    def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.ArgumentDefaultsHelpFormatter, description="Run a simulation."
    )

    parser=sargparse(parser)
    .......

I think this change makes it more confusing with the "usage: ArgumentParser(prog='sorcha-run', usage=None, description='Run a simulation.', formatter_class=<class 'argparse.ArgumentDefaultsHelpFormatter'>, conflict_handler='error', add_help=True)" bit. If you have ideas @mjuric how to get around this let me know. Otherwise I think it's easier to do what I implemented though I'll short the message to what you've written.

[mschwamb]

I figured it out. I'll get the PR in, in about half an hour.

[mschwamb]

I finally actually figured it out. Thanks to help from @bernardinelli and also the guidance of the code above. I'll also tag @bernardinelli in the review