README.md

arghelper

arghelper is a Python 3.8+ module providing functions to help with argparse.

Requirements

• argparse module from the Python Standard Library
• sys module from the Python Standard Library
• os module from the Python Standard Library

Usage

arghelper provides functions to determine if a file or directory exists:

• extant_file
• extant_dir

These can be used as follows:

if __name__ == "__main__":
    # Process the arguments
    import argparse
    import arghelper
    parser = argparse.ArgumentParser(
        description='Process the TAFFmat CET files')
    parser.add_argument(
        'config_file',
        help='CSV configuration file.',
        metavar='FILE', type=arghelper.extant_file)
    parser.add_argument(
        'input_dir',
        help='Directory containing input files.',
        metvar='DIR', type=arghelper.extant_dir)
    args = parser.parse_args()

A common pattern, for me at least, is to have three positional arguments consisting of:

1. config_file --- A configuration file
2. input_dir --- A directory containing input files to be read
3. output_dir --- A directory where the output files should be saved

This pattern has been abstracted to a Facade function called parse_config_input_output, which can be used as follows:

if __name__ == "__main__":
    # Process the arguments
    import arghelper
    args = arghelper.parse_config_input_output(sys.argv)

Another common pattern is to just parse the name of a config file:

if __name__ == "__main__":
    # Process the arguments
    import arghelper
    args = arghelper.parse_config(sys.argv)

Contributing

Contributions are welcome! To contribute please:

1. Fork the repository
2. Create a feature branch
3. Add code and tests
4. Pass lint and tests
5. Submit a pull request

Development Setup

Development Setup Using pyenv

Use the following commands to create a Python 3.9.9 virtualenv using pyenv and pyenv-virtualenv, install the requirements in the virtualenv named arghelper, and list the available [Invoke][] tasks.

$ pyenv virtualenv 3.11 arghelper
$ pyenv activate arghelper
$ pip install --upgrade pip
$ pip install -r requirements.txt
$ inv -l

License

arghelper is released under the MIT license. Please see the LICENSE.txt file for more information.