argparse-range

Easily check that an argument is within a range for argparse

Use it like this:

>>> from argparse import ArgumentParser, ArgumentTypeError
>>> from argparse_range import range_action
>>> parser = ArgumentParser()
>>> _ = parser.add_argument("rangedarg", action=range_action(0, 10), help="An argument")
>>> args = parser.parse_args(["0"])
>>> args.rangedarg
0
>>> parser.parse_args(["20"])
Traceback (most recent call last):
    ....
argparse.ArgumentTypeError: Invalid choice: 20 (must be in range 0..=10)

Features

Helptext is added transparently

foo.py --help

usage: foo.py [-h] rangedarg

positional arguments:
  rangedarg   An argument (must be in range 0..=10)

optional arguments:
  -h, --help  show this help message and exit

Infers type by default

>>> from argparse import ArgumentParser
>>> from argparse_range import range_action
>>> parser = ArgumentParser()
>>> _ = parser.add_argument("intarg", action=range_action(0, 10))
>>> _ = parser.add_argument("floatarg", action=range_action(25.0, 40.0))
>>> _ = parser.add_argument("explicit", action=range_action(25.0, 40.0), type=int)
>>> args = parser.parse_args(["5", "30", "30"])
>>> assert isinstance(args.intarg, int)
>>> assert isinstance(args.floatarg, float)
>>> assert isinstance(args.explicit, int)

Handles optional arguments and defaults just like normal parsing

>>> from argparse import ArgumentParser
>>> from argparse_range import range_action
>>> parser = ArgumentParser()
>>> _ = parser.add_argument("--maybe", action=range_action(0, 10), nargs="?")
>>> parser.parse_args([])
Namespace(maybe=None)
>>> parser.parse_args(["--maybe"])
Namespace(maybe=None)
>>> parser.parse_args(["--maybe", "5"])
Namespace(maybe=5)
>>> parser.parse_args(["--maybe", "20"])
Traceback (most recent call last):
    ....
argparse.ArgumentTypeError: Invalid choice: 20 (must be in range 0..=10)

Handles multiple arguments just like normal parsing

>>> from argparse import ArgumentParser
>>> from argparse_range import range_action
>>> parser = ArgumentParser()
>>> _ = parser.add_argument("many", action=range_action(0, 10), nargs="*")
>>> parser.parse_args([])
Namespace(many=[])
>>> parser.parse_args(["5"])
Namespace(many=[5])
>>> parser.parse_args(["1", "2", "3", "4"])
Namespace(many=[1, 2, 3, 4])