Positional

Getting stated with strings is a simple as calling clime() on an attrs class:

import attr

from clime import clime


@attr.s(auto_attribs=True)
class Dude:
    name: str  # attributes without default values in the class will be set as positional arguments in the cli

    def state_name(self):
        print(f"hi! my name is {self.name}")


def main():
    clime(Dude).state_name()


if __name__ == "__main__":
    main()

Check it:

$ python main.py

usage: tutorial_001.py [-h] name

positional arguments:
  name

optional arguments:
  -h, --help  show this help message and exit

Cool!

Dude is a normal attrs decorated class.
Name is a an argument type annotated with str.
CliMe takes the class and turns it into a CLI with the builtin ArgumentParser. Try it!

$ python main.py joe
hi! my name is joe

It works!

Want to know what will not work? No arguments:

$ python main.py
usage: tutorial_001.py [-h] name
tutorial_001.py: error: the following arguments are required: name

Or using --name as on optional argument..

$ python main.py
usage: tutorial_001.py [-h] name
tutorial_001.py: error: unrecognized arguments: --name

Note that this is an unfortunate difference between argument parser and the underlying class init. The class can take kwargs as positional. Argument parser cannot.

Anyways... that's it. All you need to take positional strings is an attrs decorated class with a str annotated class variable.