parsing non GNU-standard options using optparse in python

Question

For some reason, I have non standard command line options for my program. My program takes in a long option also with a single '-'. For example, a valid command line option would be '-f' / '-foo'. Both short and long options need to have an argument separated by space or an '='.

I am trying to parse this using the optparse, but I understand that optparse does not support non GNU-standard options. Is there a way to tweak optparse to do this?

Answer 1

Here's a mildly hackish way to do what you need.

Subclass Option and OptionParser and patch some of the methods:

from optparse import Option, OptionError, OptionParser

class MyOption(Option):
    def _set_opt_strings(self, opts):
        for opt in opts:
            if len(opt) < 2:
                raise OptionError(
                    "invalid option string %r: "
                    "must be at least two characters long" % opt, self)
            elif len(opt) == 2:
                self._short_opts.append(opt)
            else:
                self._long_opts.append(opt)

class MyOptionParser(OptionParser):
    def _process_args(self, largs, rargs, values):
        while rargs:
            arg = rargs[0]
            if arg == "--":
                del rargs[0]
                return
            elif arg[0:2] == "--":
                self._process_long_opt(rargs, values)
            elif arg[:1] == "-" and len(arg) > 1:
                if len(arg) > 2:
                    self._process_long_opt(rargs, values)
                else:
                    self._process_short_opts(rargs, values)
            elif self.allow_interspersed_args:
                largs.append(arg)
                del rargs[0]
            else:
                return 

Now you can do

parser = MyOptionParser()
parser.add_option(MyOption("-f", "-file", dest="filename",
                 help="write report to FILE", metavar="FILE"))
parser.add_option(MyOption("-q", "-quiet",
                 action="store_false", dest="verbose", default=True,
                 help="don't print status messages to stdout"))

With this, parser will accept -file as an option (and will not accept e.g. -fq).