Opster: Pythonic option parsing

http://blogg.ingspree.net/blog/2009/09/14/opster/

by Ysx • 17 years ago

24 24 17 years ago

blogg.ingspree.net

calambrac2• 17 years ago

Wait, I missed the newsletter: what don't we like about optparse?

makecheck3• 17 years ago

Apparently enough that even another alternative (Google's "argparse") is a candidate for inclusion in the next standard library, or so I thought. :)

I only have experience with the default "optparse", and not "argparse" or any others. While optparse seems like more than enough for what I use, I know of exotic command line bastardizations that optparse would never be able to handle without some tweaks.

calambrac2• 17 years ago

Looking at argparse just now, I get that one, if you need more functionality than what optparse offers, it's clearly superior. I just don't really get what opster's offering, though.

jnoller• 17 years ago

FWIW: argparse is not google's

DannoHung2• 17 years ago

I like optparse, but I wish it handled positional arguments too.

(I fully expect someone to now come and tell me how to get it to handle positional arguments easily)

makecheck3• 17 years ago

I think what you're looking for is the parse_args() method, which returns a pair; one part is the named option values, the other part is everything that's left. So you handle positional arguments by iterating over the "what's left" part.

piranha3• 17 years ago

Its API: it needs a lot of boiler plate code just to make it work, a lot of repetitions and it's object-oriented while there is no need in being so.

mr_dbr2• 17 years ago

A lot? There's about two lines I'd consider "boiler plate" (three if you count the import)

    from optparse import OptionParser

    parser = OptionParser() # initialise parser
    parser.add_option(...) # add option 1
    parser.add_option(...) # add option 2
    (options, args) = parser.parse_args() # run parser, get values

..and the sample add_option call:

    parser.add_option(
        "-q",
        "--quiet",
        action="store_false",
        dest="verbose",
        default=True,
        help="don't print status messages to stdout")

I don't see anything repetitive, nor unnecessarily object-oreiented

thristian• 17 years ago

The thing I don't like about optparse is that the documentation only mentions about half of the features. Sure, it's the most useful half, but every other standard library module has an API reference that at least mentions all the methods on every class.

For my current project at work, we're using optparse along with the configparse extension to read config files, and a bunch of monkey-patching to make it all work well together. Further development in the realm of runtime configuration is welcome, if frustratingly diverse at times.

danohuiginn2• 17 years ago

My gripe with optparse is that there's no built-in way of reading options from a config file, and allowing them to be overwritten from the command-line. I've ended up kludging together my own code to do so (as, I think, have many others), but I'd much rather have that kind of thing work out-of-the-box.

But, at first glance, this new 'opster' doesn't try to address that.

piranha3• 17 years ago

Yes, this was not my intention, though this thought is interesting, maybe I need to look into this.

mr_dbr2• 17 years ago

What about something like..

    defaults = load_stored_config_to_dict('example.conf')
    
    parser.add_option(
        "-q",
        "--quiet",
        action="store_false",
        dest="verbose",
        default=defaults['quiet'],
        help="don't print status messages to stdout")

tsally4• 17 years ago

The argument parsing file used by Lamson is pretty good.

http://bazaar.launchpad.net/%7Ezedshaw/lamson/development/an...

req23• 17 years ago

Lamson's argument parsing is directly addressed at the top of this article.

tsally4• 17 years ago

Yes I am aware, but he doesn't like it. I do.

garnet7• 17 years ago

This reminds me: did anything ever come of Zed's "Curing Python's Neglect" blog post? He wrote:

> but I realize that none of this will be fixed until > there’s a cultural shift in Python away from this > habit of Neglect.

Did that end up motivating any positive change?

Opster: Pythonic option parsing

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