my first class: Args

[Peter Kleiweg]

Scott David Daniels schreef:

> I missed the sys.argv -- here is a sketch of a slightly better rewrite:
>
>  > class Args:
>  >     """..."""
>  >     def __init__(self,usage='Usage: %(progname)s [opt...] [file...]'):
>  >         "init, usage string: embed program name as %(progname)s"
>  >         self.progname = os.path.basename(sys.argv[0])
>  > ...
>  >         self._argv = sys.argv[1:]
>    class Args:
>        """..."""
>        def __init__(self, progname, args,
>                     usage='Usage: %(progname)s [opt...] [file...]'):
>            "usage string: embed program name as %(progname)s"
>            self.progname = progname
>            self._argv = args
>            ...
>
>
>  > if __name__ == '__main__':
>  >     ...
>
>    def demo(progname, args):
>        a = Args(progname, args,
>          'Usage: %(progname)s [-a value] [-b value] [-c] word [file...]')
>        ...
>
> if __name__ == '__main__':
>       demo(sys.argv[0], sys.argv[1:])

This goes against the purpose of the class: to take care of as
much of the overhead of script writing as possible. So I can
simply do this:

    import args

    a = Args()
    for line in a:
	do_something_with(line)

Or with some extras:

    import args

    a = Args()
    for line in a:
	try:
	    do_something_with(line)
	except SomeError:
	    a.error("something wrong")

In the last example, I would get filename and line number of the
input were the error occured, in the format understood by the
'make' parser of Emacs.


-- 
Peter Kleiweg  L:NL,af,da,de,en,ia,nds,no,sv,(fr,it)  S:NL,de,en,(da,ia)
info: http://www.let.rug.nl/~kleiweg/ls.html