Black Hat Python book Netcat with Argparse

netcat.py

from argparse import ArgumentParser
import sys
import socket
import getopt
import threading
import subprocess

upload             = False

def generate_argument_parser():
    parser = ArgumentParser(description='BHP Net Tool')
    parser.add_argument('-t', help='target to listen', type=str, required=True,dest="target")
    parser.add_argument('-p', help='port to listen', type=int, required=True,dest="port")
    parser.add_argument('-l', '--listen', nargs='?', help='listen to [host]:[port] for incoming connections',default=False,const=True)
    parser.add_argument('-e', '--execute', metavar='file_to_run', type=str, help='execute the given file upon receiving a connection', default="")
    parser.add_argument('-c', '--command', nargs='?', help='initialize a command shell',default=False,const=True)
    parser.add_argument('-u', '--upload', metavar="destination", type=str, help='listen op [host]:[port] for incoming connections',default="")
    return parser

def get_arguments():
    parser = generate_argument_parser()
    args = parser.parse_args()
    return args

if __name__=="__main__":
    args = get_arguments()
    print(args)
    if not args.listen and len(args.target) and args.port > 0:
        buffer = sys.stdin.read()
        print("client_sender(buffer)")

    if args.listen:
        print("server_loop()")