Re: Re: required options

[Robert Collins, in what I hope was a joke, suggested]
> target=TARGET  ?


[to which Thorsten Kampe replied]
> That's possible? Looks /good/. Could you give me some hints on how to do
> that?

NoooOOOOOooo!!!!!

The whole reason I wrote Optik in the first place was to prevent a
proliferation of weird, non-standard option syntaxes in the Python
world.  There Should Be Only One Way To Do It, and those two ways should
be

  foo -f FILENAME

and

  foo --file=FILENAME

(Hey, it's not my fault there are two ways---no, THREE ways to do it, if
you count "foo --file FILENAME").

The admonition about required options being oxymoronic in tao.txt is
there because I want people to think twice before asking for that
feature or implementing it themselves, *not* because I think required
options should never exist.  Sometimes, a "required option" is the
least-bad solution.  It sounds like you may have stumbled across such a
situation.

See examples/required_1.py and required_2.py in the Optik source
distribution for two ways to add required options to an OptionParser.
Of course, you can always do it manually:

  if options.filename is None:
      parser.error("-f/--filename option is required")

which is what I do on the occasions where I think a required option is
the least-bad alternative.  (If you have to write that code more than
once or twice per script, you may have larger problems with your UI.)

        Greg
-- 
Greg Ward <[email protected]>                         http://www.gerg.ca/
Never try to outstubborn a cat.


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