looking for best way of giving command line arguments in python, where some params are req for some option and some params are req for other options -

hi trying send command line arguments first time. condition 1 parameter required 1 option , others other parameter.(looking user friendly). below code looks need optimization:

import argparse parser = argparse.argumentparser(description='usage options.') parser.add_argument('-o','--options',help='options available: run,rerun,kill, resume,           suspend',required=true) parser.add_argument('-c', '--config',help='config file input',type=file,required=false) parser.add_argument('-j', '--id',help='id of job',type=str,required=false) args = parser.parse_args() action_arg = list() action_arg.append(args.options) action = {'run': start_run,           'rerun': start_rerun,           'kill': kill_job,           'resume': resume_job,           'suspend': suspend_job,           'get_run': get_run,           'get_component': get_component,           'help': print_help}.get('-'.join(action_arg))  if action:     conf_file = str(args.config)     jobid = str(args.jobid)     if args.options == "run":         if conf_file == "none":             print "job configuration needed start run , job id not needed"             sys.exit(2)     elif args.options == "rerun":         if conf_file == "none" or jobid == "none":             print "job configuration , jobid needed start rerun."             sys.exit(2)     else:         if jobid == "none":             print "jobid needed perform %s action on job , configuration not needed." %args.options             sys.exit(2)     action(conf_file, jobid) else:     print "usage error:"     print_help() 

hope required params required options code. please let me know detailed explanation on requirements

this variation on script runs, , cleans several things. uses choices control options values. omits unnecessary parameters in other add_argument calls. simplifies post parse_args logic. help isn't needed since there -h option, included choice. falls through end because not in action dictionary.

import argparse import sys class stub(object):     def __init__(self,s):         self.s = s     def __call__(self,conf_file, jobid):         print self.s, conf_file, jobid parser = argparse.argumentparser(description='usage options.') parser.add_argument('-o','--options', choices=('run','rerun','kill', 'resume', 'suspend','help'),required=true) parser.add_argument('-c', '--config',help='config file input') # optionals not required; 'file' not valid type # argparse.filetype open file parser.add_argument('-j', '--jobid',help='id of job') # str default type args = parser.parse_args() # action_arg = [args.options] action = {'run': stub('start_run'),           'rerun': stub('start_rerun'),           'kill': stub('kill_job'),           'resume': stub('resume_job'),           'suspend': stub('suspend_job'),           #'get_run': get_run, # not in choices           #'get_component': get_component,           #'help': print_help,           }.get(args.options)  # what's '-'.join?  if action:     if args.options == "run":         if args.config none: # proper test none             print "job configuration needed start run , job id not needed"             sys.exit(2)     elif args.options == "rerun":         if args.config none or args.jobid none:             print "job configuration , jobid needed start rerun."             sys.exit(2)     else:         if args.jobid none:             print "jobid needed perform %s action on job , configuration not needed." %args.options             sys.exit(2)     action(args.config, args.jobid) else:     print "usage error:"     parser.print_help() 

this version replaces options choices subparsers. config , jobid become required arguments appropriate subparsers. use parents conveniently define required mix , match. argparse checking.

import argparse class stub(object):     def __init__(self,s):         self.s = s     def __call__(self,conf_file, jobid):         print self.s, conf_file, jobid  conf_parent = argparse.argumentparser(add_help=false) conf_parent.add_argument('-c', '--config',help='config file input',required=true) job_parent = argparse.argumentparser(add_help=false) job_parent.add_argument('-j', '--jobid',help='id of job',required=true)  parser = argparse.argumentparser(description='usage options.') parser.set_defaults(config=none, jobid=none) # put default value in namespace sp = parser.add_subparsers(dest='options') sp.add_parser('run',parents=[conf_parent]) sp.add_parser('rerun',parents=[conf_parent, job_parent]) sp.add_parser('kill',parents=[job_parent]) sp.add_parser('resume',parents=[job_parent]) sp.add_parser('suspend',parents=[job_parent]) args = parser.parse_args()  action = {'run': stub('start_run'),           'rerun': stub('start_rerun'),           'kill': stub('kill_job'),           'resume': stub('resume_job'),           'suspend': stub('suspend_job'),           }.get(args.options) action(args.config, args.jobid)