Re: --help option: sys.exit or return?

On 21 October 2004, Brian Dorsey said:
> This is exactly my sitation as well. 100% of my scripts which use
> optik (or really optparse) should die with a nice friendly message
> when they have trouble parsing options or really, any other error.
> 
> There is one piece of duplicate logic I end up adding to every single
> script I write though:
>     opt, args = parser.parse_args(sys.argv[1:])
>     if len(args) == 1 and args[0].lower() in ('/?', '/h', '/help'):
>         parser.print_help()
>         sys.exit(0)
> 
> It's clear from the Optik docs that the goal is unixy option parsing,
> and keeping the interface consistant. I completely agree with that.
> And yet I still find myself adding this snippet to nearly every script
> I write. Most of them are cross-platform, or windows only and I find
> that my technically oriented windows users (internal IT folks)
> universally expect to type something with a forward slash to get help.
> Without this check, any script which is OK with just one arg will
> happily try to work on "/help" or whatever.
> 
> Would you be open to adding some way to deal with this to Optik? 

Categorically, unequivocally, NO.

If you cannot achieve this by writing a simple subclass of OptionParser,
I am willing to entertain ideas for refactoring to support it.  (If you
don't know how to subclass OptionParser, I recommend the fine book
*Learning Python* by Mark Lutz and David Ascher.)

> A couple of ideas I had were:
>  * Magically use a modified STD_HELP_OPTION on windows machines.

Rule 1: no magic.  (Oh wait, that's for Quixote.  Never mind, same rule
applies in Optik, I just never wrote it down.)

>  * Add another keyword parameter to OptionParser.__init__ with a list
> of additional strings to accept as ways to print help.
>  * Allow a list of strings to be passed to the existing keyword
> parameter, something like:
> parser = optparse.OptionParser(add_help_option=['/?', '/h', '/help'])

Implement it yourself, preferably as a subclass of OptionParser, and let
us know how it worked.

        Greg
-- 
Greg Ward <[email protected]>                         http://www.gerg.ca/
One man's theology is another man's belly laugh.


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