import argparse

def demo_basic():

parser = argparse.ArgumentParser(description='demo-basic argparser')

parser.add_argument('x', type=int, help='required argument x')

parser.add_argument('-y', '--yvalue', type=int, default=233, help='optional argument y')

# parser.add_argument('move', choices=['rock', 'paper', 'scissors'])

try:

# default to sys.argv #sys.argv include xxx.py

# equivalent ['-h'], ['--help']

parser.parse_args(['--help']) #print the help information then exit

except SystemExit:

pass

args = parser.parse_args(['23'])

assert args.x==23

assert args.yvalue==233 #default

args = parser.parse_args(['23', '-y', '-233'])

assert args.x==23

assert args.yvalue==-233

args = parser.parse_args(['23', '--yvalue', '-2333'])

assert args.x==23

assert args.yvalue==-2333

def demo_array():

parser = argparse.ArgumentParser(description='demo-basic01 argparser')

parser.add_argument('x1', metavar='N', type=int, nargs='+', help='integer array')

parser.add_argument('--sum', dest='hf1', action='store_const',

const=sum, default=max, help='sum the integers (default: find the max)')

args = parser.parse_args(['--sum', '7', '-1', '42'])

assert args.hf1(args.x1)==48

def demo_true_false():

parser = argparse.ArgumentParser()

parser.add_argument('-a', action='store_true') #True if supplied, otherwise False

parser.add_argument('-b', action='store_true')

parser.add_argument('-c', action='store_false') #False if supplied, otherwise True

parser.add_argument('-d', action='store_false')

# parser.add_argument('-e', action='store_true', default=True) #useless, always True

args = parser.parse_args(['-ac'])

assert args.a

assert not args.b

assert not args.c

assert args.d