python - Argparse optional args override positional -


i'm trying figure out way have argparse positional arguments mutually exclusive optional argument.

for example:

./adder 20 32 output: 52 ./adder --interactive adder>

right now, if try '--interactive', tells me i'm missing positional arguments.

example code:

parser = argparse.argumentparser() parser.add_argument('a', metavar='first') parser.add_argument('b', metavar='second') parser.add_argument('--interactive') parser.parse_args()

i wondering if there elegant way (preferably using argparse functionality) '--interactive' disables requirement of using 2 positional arguments.

usually positional arguments can not omitted. can try nargs='*' alternative.

parser = argparse.argumentparser() parser.add_argument('ab', nargs='*', type='int') parser.add_argument('--interactive', action='store_true') args = parser.parse_args()

use list args.ab store positional argument. if omitted, args.ab empty list.


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