Single function

In a file named 1-single-function.py:

from argparse import Namespace

from arger import Arger
from tests.utils import _reprint


def main(param1: int, param2: str, _namespace_: Namespace, kw1=None, kw2=False):
    """Example function with types documented in the docstring.

    :param param1: The first parameter.
    :param param2: The second parameter.
    :param kw1: this is optional parameter.
    :param kw2: this is boolean. setting flag sets True.
    """
    _reprint(**locals())


arger = Arger(
    main,
    prog="pytest",  # for testing purpose. otherwise not required
)

if __name__ == "__main__":
    arger.run()

Usage

• Show help message

  $ python docs/examples/1-single-function.py -h
  usage: pytest [-h] [-k KW1] [-w] param1 param2
  
  Example function with types documented in the docstring.
  
  positional arguments:
    param1         The first parameter.
    param2         The second parameter.
  
  options:
    -h, --help     show this help message and exit
    -k, --kw1 KW1  this is optional parameter. (default: None)
    -w, --kw2      this is boolean. setting flag sets True. (default: False)
  

• Run with required positional arguments

  $ python docs/examples/1-single-function.py 10 p2
  _namespace_ (<class 'argparse.Namespace'>): [('__func_0', '_dispatch'), ('__level__', 0), ('kw1', None), ('kw2', False), ('param1', 10), ('param2', 'p2')]
  kw1 (<class 'NoneType'>): None
  kw2 (<class 'bool'>): False
  param1 (<class 'int'>): 10
  param2 (<class 'str'>): p2
  

• Running without required arguments raises an error

  $ python docs/examples/1-single-function.py
  usage: pytest [-h] [-k KW1] [-w] param1 param2
  pytest: error: the following arguments are required: param1, param2
  

• Running with an invalid flag raises an error

  $ python docs/examples/1-single-function.py --invalid
  usage: pytest [-h] [-k KW1] [-w] param1 param2
  pytest: error: the following arguments are required: param1, param2
  

• Running with an incorrect type for a positional argument raises a type error

  $ python docs/examples/1-single-function.py p1 p2
  usage: pytest [-h] [-k KW1] [-w] param1 param2
  pytest: error: argument param1: invalid int value: 'p1'