argparse-utils 1.1.0

A collection of utilities for the Python standard-library argparse module

argparse_utils

argparse_utils provides a collection of utilities for the Python standard-library argparse module. These utilities assist with parsing command-line arguments to Python objects.

Example

Consider a simple command-line script which accepts a colour as it's only argument, and immediately prints the Python representation of that object.

from argparse import ArgumentParser
from enum import Enum

from argparse_utils import enum_action

class Colours(Enum):
    red = 1
    green = 2
    blue = 3

if __name__ == "__main__":
    parser = ArgumentParser()
    parser.add_argument('colour', action=enum_action(Colours))

    arguments = parser.parse_args()

    print(repr(arguments.colour))

$ argparse_utils_example.py red
<Colours.red: 1>

Without the enum_action action, arguments.colour would be the string 'red', rather than the enum value Colours.red. What's more, the action ensures that only the values given in the enum are allowed, instead of any string value.

Reference

• mapping_action(possible_values)

  Takes a dictionary whose keys are the allowed values, and maps those values to the values found in the dictionary. Only the values found as keys in the dictionary are allowed as command-line arguments.

  eg. An action of

  mapping_action({
      'red': (255, 0, 0),
      'green': (0, 255, 0),
      'blue': (0, 0, 255)
  })
  

  would map a command-line argument of red to the Python object (255, 0, 0).

• enum_action(enum_class)

  Takes an Enum class, and maps the string representation of the keys to the appropriate enum value. Only the values found in the enum are allowed as command-line arguments.

  eg. Using the Colour enum, from the first example, an action of

  enum_action(Colour)
  

  would map a command-line argument of red to the enum Colour.red value.