OptionParser python module - multiple entries of same variable?

问题

I'm writing a little python script to get stats from several servers or a single server, and I'm using OptionParser to parse the command line input.

#!/usr/bin/python

import sys
from optparse import OptionParser
...
parser.add_option("-s", "--server", dest="server", metavar="SERVER", type="string", 
                  help="server(s) to gather stats [default: localhost]")
...

my GOAL is to be able to do something like

#test.py -s server1 -s server2

and it would append both of those values within the options.server object in some way so that I could iterate through them, whether they have 1 value or 10.

Any thoughts / help is appreciated. Thanks.

回答1:

import optparse

parser = optparse.OptionParser()
parser.add_option('-t', '--test', action='append')

options, args = parser.parse_args()
for i, opt in enumerate(options.test):
    print 'option %s: %s' % (i, opt)

回答2:

Yes, it can be done with optparse.

This is an example:

./test.py --categories=aaa --categories=bbb --categories ccc arg1 arg2 arg3

which prints:

arguments: ['arg1', 'arg2', 'arg3']
options: {'categories': ['aaa', 'bbb', 'ccc']}

Full working example below:

#!/usr/bin/env python

import os, sys
from optparse import OptionParser
from optparse import Option, OptionValueError

VERSION = '0.9.4'

class MultipleOption(Option):
    ACTIONS = Option.ACTIONS + ("extend",)
    STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",)
    TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",)
    ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",)

    def take_action(self, action, dest, opt, value, values, parser):
        if action == "extend":
            values.ensure_value(dest, []).append(value)
        else:
            Option.take_action(self, action, dest, opt, value, values, parser)


def main():
    PROG = os.path.basename(os.path.splitext(__file__)[0])
    long_commands = ('categories')
    short_commands = {'cat':'categories'}
    description = """Just a test"""
    parser = OptionParser(option_class=MultipleOption,
                          usage='usage: %prog [OPTIONS] COMMAND [BLOG_FILE]',
                          version='%s %s' % (PROG, VERSION),
                          description=description)
    parser.add_option('-c', '--categories', 
                      action="extend", type="string",
                      dest='categories', 
                      metavar='CATEGORIES', 
                      help='comma separated list of post categories')

    if len(sys.argv) == 1:
        parser.parse_args(['--help'])

    OPTIONS, args = parser.parse_args()
    print "arguments:", args
    print "options:", OPTIONS

if __name__ == '__main__':
    main()

More information at http://docs.python.org/library/optparse.html#adding-new-actions

回答3:

You could try to check out argparse. It provides "nargs" parameter meaning you would be able to do something along

#test.py -s server1 server2

I know that's not exactly what requested but it might be a decent compromise without too much hassle. :)

回答4:

Could be easier to accept a comma-separated list of servers:

# test.py -s server1,server2

and split the value within your script.

回答5:

Here is a known working example (from http://docs.python.org/library/email-examples.html):

parser.add_option('-r', '--recipient',
                  type='string', action='append', metavar='RECIPIENT',
                  default=[], dest='recipients',
                  help='A To: header value (at least one required)')

I think the usages is something like:

python script.py -r some@where.com -r no@where.com -r any@where.com

来源：https://stackoverflow.com/questions/2756062/optionparser-python-module-multiple-entries-of-same-variable

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optionparser