How can I get optparse's OptionParser to ignore invalid options?

Question

In python\'s OptionParser, how can I instruct it to ignore

Answer 1

Here's one way to have unknown arguments added to the result args of OptionParser.parse_args, with a simple subclass.

from optparse import (OptionParser,BadOptionError,AmbiguousOptionError)

class PassThroughOptionParser(OptionParser):
    """
    An unknown option pass-through implementation of OptionParser.

    When unknown arguments are encountered, bundle with largs and try again,
    until rargs is depleted.  

    sys.exit(status) will still be called if a known argument is passed
    incorrectly (e.g. missing arguments or bad argument types, etc.)        
    """
    def _process_args(self, largs, rargs, values):
        while rargs:
            try:
                OptionParser._process_args(self,largs,rargs,values)
            except (BadOptionError,AmbiguousOptionError), e:
                largs.append(e.opt_str)

And here's a snippet to show that it works:

# Show that the pass-through option parser works.
if __name__ == "__main__": #pragma: no cover
    parser = PassThroughOptionParser()
    parser.add_option('-k', '--known-arg',dest='known_arg',nargs=1, type='int')
    (options,args) = parser.parse_args(['--shazbot','--known-arg=1'])    
    assert args[0] == '--shazbot'
    assert options.known_arg == 1

    (options,args) = parser.parse_args(['--k','4','--batman-and-robin'])
    assert args[0] == '--batman-and-robin'
    assert options.known_arg == 4