python argparse subparser assign value to variable

Question

i want to assign the subparser values to a variable like 'rport' so when the user call argument with value like

python example.py -sock connectmode -rport 10000 

the rport variable take the 10000 int value but that code return error in the last line in 'rport = '

AttributeError: 'Namespace' object has no attribute 'rport'

notes : the subparsers is for a function is called 'socketfunc' i wanted them to be a subargs for '-sock' argument when i execute : 'python example.py -sock connectmode -h return the secondary_parser args [!]another note : the rport and rhost variables is global to make their values available to all functions

any help ! and thanks.

the code is :

import argparse
import socket
parser = argparse.ArgumentParser(epilog='\tExample: \r\npython ' + sys.argv[0])
parser.error = parser_error
parser._optionals.title = "OPTIONS"
subparsers = parser.add_subparsers(help='Specify secondary options')
global rport , rhost
secondary_parser = subparsers.add_parser('connectmode', help='sock argument connectmode')
listenmode_parser = subparsers.add_parser('listenmode',help='sock argument listenmode')
parser.add_argument('-sock','--socket',help="tcp socket functions [!] support only ipv4 for now",action="store_true")
secondary_parser.add_argument('-rport','--remoteport',help="destination port to connect to",required=True,action='store')
secondary_parser.add_argument("-rhost",'--destination',help="destination host ip addr",required=True,action='store')
secondary_parser.set_defaults(func=socketfunc)
listenmode_parser.set_defaults(func=socketfunc)
args = parser.parse_args()
rport = args.rport

Answer 1

import sys

def getcmdlineargv(argv):
"""Function to get values from cmd line and converted into dictionary"""
   opts = {}  # dictionary to store key-value pairs.
   while argv:  # until arguments left to parse...
      if argv[0][0] == '-':  # Found a "-name value" pair.
        opts[argv[0]] = argv[1]  # Add key and value to the dictionary.
      argv = argv[1:]  # Reduce the argument list by copying it starting from index 1.
   return opts
argvDict = getcmdlineargv(sys.argv)
print(argvDict)

>>> python filename.py -sock connectmode -rport 10000
>>> {'-sock': 'connectmode', '-rport': '10000'}

Using argument parser:

import argparse

parser = argparse.ArgumentParser()
parser.add_argument("-sock", type=str, help='')
parser.add_argument("-rport", type=int, help='')
parsarg = vars(parser.parse_args())
print(parsarg.get('rport'))

>>> python filename.py -sock connectmode -rport 10000
>>> 10000

Hope this will solve your problem to get command line argument.

Answer 2

hello guys the soloution is that replace rport = args.rport with rport=args.remoteport the short arg doesnt conain the value but should specify the long arg name

thanks for all.

Answer 3

It's hard to figure out what you want. The description is poorly formated and rambling. But I'll try to explain what your code is doing.

Simplified a bit:

import argparse

parser = argparse.ArgumentParser()
parser._optionals.title = "OPTIONS"
subparsers = parser.add_subparsers(help='Specify secondary options')
global rport , rhost
secondary_parser = subparsers.add_parser('connectmode', help='sock argument connectmode')
listenmode_parser = subparsers.add_parser('listenmode',help='sock argument listenmode')
parser.add_argument('-sock','--socket',action="store_true")
secondary_parser.add_argument('-rport','--remoteport',required=True)
secondary_parser.add_argument("-rhost",'--destination',required=True)
secondary_parser.set_defaults(func='secondary')
listenmode_parser.set_defaults(func='listen')
args = parser.parse_args()
print(args)

With the connectmode values:

1027:~/mypy$ python3 stack48264081.py  -sock connectmode -rport 10000 
usage: stack48264081.py connectmode [-h] -rport REMOTEPORT -rhost DESTINATION
stack48264081.py connectmode: error: the following arguments are required: -rhost/--destination

Why? Because you defined -rhost as a required argument for the connectmode subparser. If I provide both:

1031:~/mypy$ python3 stack48264081.py  -sock connectmode -rport 10000 -rhost foo
Namespace(destination='foo', func='secondary', remoteport='10000', socket=True)

In this case args.remoteport would work. args.rport would not, because the dest is taken from the long name, -- , not the short one.

1034:~/mypy$ python3 stack48264081.py  listenmode
Namespace(func='listen', socket=False)

args.remoteport would not work here because that argument is not defined for this subparser.

-sock is a simple True/False argument, and has nothing to do with the subparsers.