config-argument-parser 0.5.2

A package help automatically create command-line interface from configuration or code.

config-argument-parser

A package help automatically create command-line interface from configuration or code.

Motivation

Configuration files are highly readable and useful for specifying options, but sometimes they are not convenient as command-line interface. However, it requires writing a lot of code to produce a CLI. This module automates the building process, by utilizing the Python standard libraries configparser and argparse.

Features

• Only a few lines are needed to build a CLI from an existing script.
• The comments are parsed as help messages. (Most libraries do not preserve the comments.)
• Consistent format between configuration and script provides ease of use.

Usage

Case 1: create CLI from configuration

Create an example script example.py:

import configargparser

parser = configargparser.ConfigArgumentParser()
parser.read("config.ini")
# add short options for the first few arguments in order
# default is parser.add_arguments()
parser.add_arguments(shorts="sfb")
parser.parse_args()

print("Configs:", parser.defaults)
print("Args:   ", parser.args)

Create a configuration file config.ini in the same directory:

[DEFAULT]
# Help message of the first argument. Help is optional.
a_string = 'abc'
a_float = 1.23  # inline comments are omitted
# Help can span multiple lines.
# This is another line.
a_boolean = False
an_integer = 0

Show help, python example.py -h:

usage: example.py [-h] [-s A_STRING] [-f A_FLOAT] [-b]
                  [--an_integer AN_INTEGER]

optional arguments:
  -h, --help            show this help message and exit
  -s A_STRING, --a_string A_STRING
                        Help message of the first argument. Help is optional.
                        (default: abc)
  -f A_FLOAT, --a_float A_FLOAT
                        (default: 1.23)
  -b, --a_boolean       Help can span multiple lines. This is another line.
                        (default: False)
  --an_integer AN_INTEGER
                        (default: 0)

Regular run, python example.py:

Configs: {'a_string': 'abc', 'a_float': 1.23, 'a_boolean': False, 'an_integer': 0}
Args:    {'a_string': 'abc', 'a_float': 1.23, 'a_boolean': False, 'an_integer': 0}

Run with options, such as python example.py -b -f 1:

Configs: {'a_string': 'abc', 'a_float': 1.23, 'a_boolean': False, 'an_integer': 0}
Args:    {'a_string': 'abc', 'a_float': 1.0, 'a_boolean': True, 'an_integer': 0}

Case 2: create CLI from script itself

Create a script example.py, with the variables defined at top of file as below:

# [DEFAULT]
# Help message of the first argument. Help is optional.
a_string = "abc"
a_float = 1.23  # inline comments are omitted
# Help can span multiple lines.
# This is another line.
a_boolean = False
an_integer = 0
# [END]

import configargparser

parser = configargparser.ConfigArgumentParser()
parser.read_py("example.py")
parser.add_arguments(shorts="sfb")
parser.parse_args()

# update global variables
globals().update(parser.args)
print(a_string)
print(a_float)
print(a_boolean)
print(an_integer)

Use it as in case 1. For example, python example.py -b -f 1:

abc
1.0
True
0

Note that the values are changed.

Case 3: create CLI from an object

Create a script example.py as below. Default arguments are defined as class attributes, and parsed arguments are stored as instance attributes. The good is that auto-completion can be triggered in editors.

import configargparser

class Args:
    # Help message of the first argument. Help is optional.
    a_string = "abc"
    a_float = 1.23  # inline comments are omitted
    # Help can span multiple lines.
    # This is another line.
    a_boolean = False
    an_integer = 0

args = Args()

parser = configargparser.ConfigArgumentParser()
parser.parse_obj(args, shorts="sfb")

print(args.a_string)
print(args.a_float)
print(args.a_boolean)
print(args.an_integer)

Use it as in case 1. For example, python example.py -b -f 1:

abc
1.0
True
0

Installation

Install from PyPI:

python -m pip install --upgrade pip
pip install config-argument-parser

Alternatively, install from source:

git clone https://github.com/yuanx749/config-argument-parser.git
cd config-argument-parser

then install in development mode:

git checkout main
python -m pip install --upgrade pip
pip install -e .

or:

git checkout dev
python -m pip install --upgrade pip
pip install -e .[dev]
pre-commit install

Uninstall:

pip uninstall config-argument-parser

Notes

This package uses Semantic Versioning.