https://github.com/devforfu/ancli

Building argument parser from a function annotation
https://github.com/devforfu/ancli

argparse cli package pip python

Last synced: about 1 month ago
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Building argument parser from a function annotation

• Host: GitHub
• URL: https://github.com/devforfu/ancli
• Owner: devforfu
• License: mit
• Created: 2019-06-27T18:54:21.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2019-10-17T19:44:56.000Z (over 5 years ago)
• Last Synced: 2024-11-29T13:59:29.515Z (about 2 months ago)
• Topics: argparse, cli, package, pip, python
• Language: Python
• Homepage: https://pypi.org/project/ancli/
• Size: 82 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.rst
  • License: LICENSE

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README

        
ancli

=====

.. image:: https://i.imgur.com/5hCKc9u.png

    :target: https://i.imgur.com/5hCKc9u.png

    :align: center

Building argument parser from a function annotation. A simple utility inspired by

``Fire`` and ``docopt``. Ad-hoc solution for someone who often writes scripts with a

single entry point.

How?

----

The process of building CLI with ``ancli`` is very simple.

1. Write a plain Python function with annotated parameters.

2. Wrap it with ``make_cli``.

3. Run your script.

Examples

--------

1. Function with annotated parameters

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The function ``run`` has explicitly annotated parameters and its signature is used

to instantiate ``argparse.ArgumentParser`` instance that accepts parameters with

specific types and default (if any) parameters. If default value is not provided,

then the parameter is considered to be required.

.. code:: python

    from ancli import make_cli

    def run(path: str, flag: bool = True, iterations: int = 1):

        print(f'run: path={path}, flag={flag}, iterations={iterations}')

    if __name__ == '__main__':

        make_cli(run)

Now this snippet can be used as follows.

.. code:: bash

    $ python script.py --path file.txt --flag 0

    run: path=file.txt, flag=False, iterations=1

2. Function without annotations

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The functions without type annotations try to infer the parameters types based

on their default values.

.. code:: python

    from ancli import make_cli

    def run(a, b=2, c=3.0):

        for param in (a, b, c):

            print(type(param))

    if __name__ == '__main__':

        make_cli(run)

The parameters without default values are considered as strings.

.. code:: bash

    $ python script.py --a 1 --b 2 --c 3.0

    

    

    

3. Running ``ancli`` as a module

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Running package as a module allows to dynamically build a CLI from some function. 

You just need to specify a path to the module, and function which should be 

treated as an entry point.

.. code:: bash

    $ python -m ancli examples.functions:compute --a 2 --b 6

    42