extra arguments are not tolerated by the parser, even with Extra.ignore

[lpasselin]

The parser raises an error when extra arguments are provided.

It could be useful to only parse known args.
For example, ifMyPydanticModel.Config.extra == pydantic.Extra.ignore, use parser.parse_known_args() to tolerate extra arguments.

[mpkocher]

I'm not sure that strongly coupling the model config of extras=ignore|forbid|allow semantics with the command line semantics would always be desired or expected behavior.

The current workaround for this case is to explicitly add an 'cli_args', 'others' or similar keyword to your Pydantic model.

from typing import Optional

from pydantic import BaseModel

from pydantic_cli import run_and_exit


class Options(BaseModel):
    alpha: int
    beta: float
    others: Optional[str]


def example_runner(opts: Options) -> int:
    print(f"Mock example running with {opts}")
    return 0


if __name__ == "__main__":
    run_and_exit(Options, example_runner, description=__doc__, version="0.1.0")

Running

$> python pydantic_cli_with_extras.py --alpha 1 --beta 1 --others '--pass-through-options 1234 a=1 b=2'
Mock example running with alpha=1 beta=1.0 others='--pass-through-options 1234 a=1 b=2'

[lpasselin]

Consider the situation where the user cannot modify the arguments passed in the terminal.
We only want to parse some arguments and ignore others.

Also, by default, BaseModel.Config.extra == Extra.ignore.

[mpkocher]

Also, by default, BaseModel.Config.extra == Extra.ignore.

I think that pydantic's default of Extra.ignore would create a lot of frustrating and difficult to debug cases at the command line level. Having the default behavior to ignore unrecognized arguments seems like a lackluster default user experience. It would also be easy to miss this key behavior in docs unless it's documented in a several of places.

Also, pydantic_cli doesn't uses any of the core config values pydantic.BaseConfig to avoid getting tangled up with trying to attempting to interpret these semantically. To namespace the pydantic_cli config values, it defines settings using the "CLI_*" keys.

[lpasselin]

Ok, thank you for your help. Fell free to reject the associated PR and close this issue if you have no plans on adding an option to ignore extra arguments.

I will most likely fork the project to fit my personal needs.

[mpkocher]

I don't think that using Extra.* will work.

However, adding a new key to the config of CLI_IGNORE_EXTRAS:bool = False seems like a reasonable compromise?

https://github.com/mpkocher/pydantic-cli/blob/master/pydantic_cli/core.py

[mpkocher]

@lpasselin Adding a PR that is very similar to one you closed but leveraging CLI_IGNORE_EXTRAS will probably work.

Please add an inline docs to the DefaultConfig in core.py and add a new test and we should be good to go.

Thanks for the feedback and comments.