Actions
Finally, you can assign actions to an argument.
The default action that we have been using is store (store the value).
Here are some other actions:
- Store a constant if the user specifies a **flag(( (an option without any value).
parser = argparse.ArgumentParser()
parser.add_argument("--magic", action="store_const", const=42)
args = parser.parse_args()
print(args) # Namespace(magic=42) if --magic is specified, Namespace(magic=None) otherwise.
- Store
True/Falseif the user specifies a flag
parser.add_argument("--play", action="store_true")
parser.add_argument("--sleep", action="store_false")
- Append instances of an argument into a list. Allows users to specify more than one value for an option.
parser = argparse.ArgumentParser()
parser.add_argument("--input", action="append")
print(parser.parse_args())
$ python test.py --input 1 --input 2 --input 3 --input 4
Namespace(input=['1', '2', '3', '4'])