argson 0.2.1

Manage arguments from a JSON file

argson

Arguments from JSON

Deploy arguments into a python program from a JSON config file

Installation

pip install argson

python3 setup.py install

Currently not supporting Python 2. Should work on all Python 3 versions. Tested with Python 3.7.1

Basic usage

config/arguments.json

[
  {
    "flags": ["--string-to-print"]
  }
]

config/defaults.json

{
  "string_to_print": "foo"
}

main.py

import argson

arguments = argson.parse_file_and_arguments()
print(arguments.string_to_print)

$ python main.py # -> foo

$ python main.py --string bar # -> bar

Documentation

argson.parse_file_and_arguments

Used to automatically parse the arguments file, self file and defaults file, generating an object with the flags from the arguments file

Arguments:

Argument	Type	Default	Description
config_file	str	config/arguments.json	where arguments are read
self_file	str	config/self.json	configurations for argparse.ArgumentParser
defaults_file	str	config/defaults.json	default values for arguments
working_dir	str	os.getcwd()	where the program will look for files to load
no_builtins	bool	False	disables built-in flags
verbose	bool	False	disables error messages

Returns: object with attributes from config_file flags

argson.parse_config_file

Used when there is need to manipulate the instance of ArgumentParser and the array of remaining arguments to parse

Arguments: same as argson.parse_file_and_arguments

Returns: Tuple[ArgumentParser, List[string]]. The instance of ArgumentParser and a list of the remaining arguments to be parsed. If the return value is assigned like argument_parser, remaining_args = argson.parse_config_file() the remaining args can be then parsed as in arguments = argument_parser.parse_args(remaining_args), which is basically what parse_file_and_arguments does.

config_file

A json file containing an array of objects with at least one key called flags. Those are the flags with which the program will be called in "hyphen-case" starting with --, like in the example. Extra keys can be passed to express the flag behaviour or help string that will be displayed when the program is called with --help. Those are the same attributes that can be passed to ArgumentParser.add_argument

self_file

A json file containing information about the main ArgumentParser instance. Those are the same attributes supported by argparse.ArgumentParser

defaults_file

A json file with the default values of the flags in snake_case. That is, if an argument has a flag string-to-parse, the default value must be read as string_to_parse. Refer to the example above.

why decouple configs_file and defaults_file?

It is best to decouple those files so we can programatically select the defaults source, maintaining the same configurations for the flags. That is sometimes necessary when deploying scripts that have different defaults when running in development and in production environments.

Contributing

• fork and clone this repo
• install pipenv
• pipenv install
• code like there is no tomorrow
• submit PR
• ??
• we profit together

Open for suggestions!