Keywords to command line arguments

Convert your function with keyword arguments into command line arguments with one line of code.

Installation

pip install keyword2cmdline

Usage

Use the decorator command from the keyword2cmdline module to convert the function into command line arguments.

from keyword2cmdline import command

@command
def main(text="Hello world",
         language='en.US',
         exclamation_number=2,
         exclamation_sign="!",
         exclamation=True):
     ...


if __name__ == '__main__':
    main()

Check the example examples/hello_world.py.

$ python examples/hello_world.py -h
usage: hello_world.py [-h] [--exclamation_number EXCLAMATION_NUMBER]
                      [--exclamation_sign EXCLAMATION_SIGN]
                      [--exclamation EXCLAMATION] [--text TEXT]
                      [--language LANGUAGE]

optional arguments:
  -h, --help            show this help message and exit
  --exclamation_number EXCLAMATION_NUMBER
  --exclamation_sign EXCLAMATION_SIGN
  --exclamation EXCLAMATION
  --text TEXT
  --language LANGUAGE

$ python examples/hello_world.py
Hello world!!

>>> from examples.hello_world import main
>>> main.set_sys_args([])()
Hello world!!

$ python examples/hello_world.py --exclamation_number 10
Hello world!!!!!!!!!!

>>> from examples.hello_world import main
>>> main.set_sys_args("--exclamation_number 10".split())()
Hello world!!!!!!!!!!

$ python examples/hello_world.py --language hi.IN
नमस्ते दुनिया!!

>>> from examples.hello_world import main
>>> main.set_sys_args("--language hi.IN".split())()
नमस्ते दुनिया!!

For boolean variables, any string is True but empty string '' is False (you can customize that)

$ python examples/hello_world.py --exclamation ''
Hello world

>>> from examples.hello_world import main
>>> main.set_sys_args( ["--exclamation", ""])()
Hello world

To add help and more customization to the ArgumentParser.add_argument() see the example in examples/hello_world_customizations.py. Basically import a dummy class opts from keyword2cmdline and then pass all the arguments as if opts is a dict.

from keyword2cmdline import command, opts

@command
def main(text="Hello world",
         language='en.US',
         exclamation_number=2,
         exclamation_sign="!",
         exclamation=opts(
               default=True,
               type=bool,
               help="""Whether to use exclamation sign or not. Use empty string '' for False""")):
     ...


if __name__ == '__main__':
    main()

Asking for help will print the keyword help.

$ python examples/hello_world_customizations.py -h
usage: hello_world_customizations.py [-h]
                                     [--exclamation_sign EXCLAMATION_SIGN]
                                     [--exclamation EXCLAMATION] [--text TEXT]
                                     [--language LANGUAGE]
                                     [--exclamation_number EXCLAMATION_NUMBER]

Prints hello world with desired number of exclamation signs

optional arguments:
  -h, --help            show this help message and exit
  --exclamation_sign EXCLAMATION_SIGN
  --exclamation EXCLAMATION
                        Whether to use exclamation sign or not. Use empty
                        string '' for False.
  --text TEXT
  --language LANGUAGE
  --exclamation_number EXCLAMATION_NUMBER

Support for Variational **kwargs

(New feature in v1.0)

>>> from keyword2cmdline import command
>>> first = lambda xs: xs[0]
>>> @command
... def main(text="sum", **kw):
...     return dict(kw, text=text)
>>> _ = main.set_sys_args(sys_args = "--text sum --a 1 --b 2 --c 3".split())
>>> list(sorted(main().items(), key=first))
[('a', '1'), ('b', '2'), ('c', '3'), ('text', 'sum')]

Support for click like boolean parser

(New feature in v1.0)

from keyword2cmdline import click_like_command

@click_like_command
def main(text="Hello world",
         language='en.US',
         exclamation_number=2,
         exclamation_sign="!",
         exclamation=True):
    ...

$ python examples/hello_world.py --exclamation False
Hello world

>>> from examples.hello_world_click import main
>>> main.set_sys_args( ["--exclamation", "False"])()
Hello world

Support for argcomplete, lists, dicts and enums

(New feature in v1.3.0)

list and dict are parsed using json.loads. dict are merged with the default dict argument. enum.Enum are converted to strings and the corresponding string can be converted back to the enum object. A convenience class keyword2cmdline.EnumChoice is provided for using shortnames for enum object which might use long names to support argcomplete feature consistently.

>>> from keyword2cmdline import command, EnumChoice
>>> @command
... def main(text="Hello world",
...          language=EnumChoice('Lang', 'en_US hi_IN').en_US,
...          exclamation_props=dict(number=2),
...          exclamation=True):
...     return sorted(locals().items())
...
>>> main.set_sys_args([])()
[('exclamation', True), ('exclamation_props', {'number': 2}), ('language', <Lang.en_US: 1>), ('text', 'Hello world')]
>>> main.set_sys_args(["--exclamation", ""])()
[('exclamation', False), ('exclamation_props', {'number': 2}), ('language', <Lang.en_US: 1>), ('text', 'Hello world')]
>>> main.set_sys_args(["--language", "hi_IN"])()
[('exclamation', True), ('exclamation_props', {'number': 2}), ('language', <Lang.hi_IN: 2>), ('text', 'Hello world')]
>>> main.set_sys_args(["--exclamation_props", '{"number": 3}'])()
[('exclamation', True), ('exclamation_props', {'number': 3}), ('language', <Lang.en_US: 1>), ('text', 'Hello world')]

>>> from keyword2cmdline import click_like_command
>>> @click_like_command
... def main(text="Hello world",
...          language=EnumChoice('Lang', 'en_US hi_IN').en_US,
...          exclamation_props=dict(number=2),
...          exclamation=True):
...     return sorted(locals().items())
...
>>> main.set_sys_args(["--exclamation", "False"])()
[('exclamation', False), ('exclamation_props', {'number': 2}), ('language', <Lang.en_US: 1>), ('text', 'Hello world')]

Support for recursive configs using command_config

(New feature in v2.0.0)

Recursive functions are handled by constructing partials of functions that are marked with @command_config.

>>> from keyword2cmdline import command, EnumChoice, command_config
>>> @command_config
... def exclamation(number=2,
...                 sign="!",
...                 use=True):
...     return sorted(locals().items())
>>> @command
... def main(text="Hello world",
...          language=EnumChoice('Lang', 'en_US hi_IN').en_US,
...          exclamation=exclamation):
...     return [("text", text), ("language", language)] + [
...            ("exclamation." + k, v)
...            for k, v in sorted(exclamation.keywords.items()) ]
>>> main.set_sys_args(["--exclamation.use", "True", "--exclamation.sign", "?"])()
[('text', 'Hello world'), ('language', <Lang.en_US: 1>), ('exclamation.number', 2), ('exclamation.sign', '?'), ('exclamation.use', True)]


A click like handling of booleans is available with `click_like_command_config`
and `click_like_command`.

``` python-console
>>> from keyword2cmdline import click_like_command, EnumChoice, click_like_command_config
>>> @click_like_command_config
... def exclamation(number=2,
...                 sign="!",
...                 use=True):
...     return sorted(locals().items())
>>> @click_like_command
... def main(text="Hello world",
...          language=EnumChoice('Lang', 'en_US hi_IN').en_US,
...          exclamation=exclamation):
...     return [("text", text), ("language", language)] + [
...            ("exclamation." + k, v)
...            for k, v in sorted(exclamation.keywords.items()) ]
>>> main.set_sys_args(["--exclamation.use", "False", "--exclamation.sign", "?"])()
[('text', 'Hello world'), ('language', <Lang.en_US: 1>), ('exclamation.number', 2), ('exclamation.sign', '?'), ('exclamation.use', False)]