[Python-Dev] Re: Call for reviewer! (original) (raw)

David Goodger dgoodger@bigfoot.com
Tue, 15 Aug 2000 22:36:02 -0400

I thought the "backwards compatibility" issue might be a sticking point ;> And I can see why.

So, if I were to rework the patch to remove the incompatibility, would it fly or still be shot down? Here's the change, in a nutshell:

Added a function getoptdict(), which returns the same data as getopt(), but instead of a list of [(option, optarg)], it returns a dictionary of {option:optarg}, enabling random/direct access.

getoptdict() turns this:

if __name__ == '__main__':
    import getopt
    opts, args = getopt.getopt(sys.argv[1:], 'a:b')
    if len(args) <> 2:
        raise getopt.error, 'Exactly two arguments required.'
    options = {'a': [], 'b': 0}  # default option values
    for opt, optarg in opts:
        if opt == '-a':
            options['a'].append(optarg)
        elif opt == '-b':
            options['b'] = 1
    main(args, options)

into this:

if __name__ == '__main__':
    import getopt
    opts, args = getopt.getoptdict(sys.argv[1:], 'a:b',
                                   repeatedopts=APPEND)
    if len(args) <> 2:
        raise getopt.error, 'Exactly two arguments required.'
    options = {'a': opts.get('-a', [])}
    options['b'] = opts.has_key('-b')
    main(args, options)

(Notice how the defaults get subsumed into the option processing, which goes from 6 lines to 2 for this short example. A much higher-level interface, IMHO.)

BUT WAIT, THERE'S MORE! As part of the deal, you get a free test_getopt.py regression test module! Act now; vote +1! (Actually, you'll get that no matter what you vote. I'll remove the getoptdict-specific stuff and resubmit it if this patch is rejected.)

The incompatibility was introduced because the current getopt() returns an empty string as the optarg (second element of the tuple) for an argumentless option. I changed it to return None. Otherwise, it's impossible to differentiate between an argumentless option '-a' and an empty string argument '-a ""'. But I could rework it to remove the incompatibility.

Again: If the patch were to become 100% backwards-compatible, with just the addition of getoptdict(), would it still be rejected, or does it have a chance?

Eagerly awaiting your judgement...

-- David Goodger dgoodger@bigfoot.com Open-source projects: