Complicated use case

[MartenBE]

Hello, I've read the documentation, but am uncertain how I can implement the following options:

• --version to give the version.
• --config-file to point to an other config file. Default should be .test.yml, .test.yaml.
• --check a CLI only boolean flag (not in yaml)
• --width can both be set on CLI or in the yml file, is default 50.
• --accepted-values is a list of codes, can be set on the CLI or in the yaml file.
• FILENAMES is a postional list of filenames (nargs + so to speak)

I've come up with the following so far, but am unsure how to insert the --version and --config-file options to do as expected:

class Settings(BaseSettings):
    filenames: CliPositionalArg[list[str]]
    check: CliImplicitFlag[bool] = False
    width: int = 50
    accepted_values: list[str] = []

    @classmethod
    def settings_customise_sources(
        cls,
        settings_cls: Type[BaseSettings],
        init_settings: PydanticBaseSettingsSource,
        env_settings: PydanticBaseSettingsSource,
        dotenv_settings: PydanticBaseSettingsSource,
        file_secret_settings: PydanticBaseSettingsSource,
    ) -> Tuple[PydanticBaseSettingsSource, ...]:
        return (
            CliSettingsSource(settings_cls, cli_parse_args=True),
            YamlConfigSettingsSource(settings_cls, yaml_file=[".ski-lint.yml", ".ski-lint.yaml"]),
        )

The docs are rather confusing ... .

[hramezani]

I've come up with the following so far, but am unsure how to insert the --version and --config-file options to do as expected:

Can't you add fields for these two fields like other fields? what is the difference between these two fields and others?

[MartenBE]

@hramezani

• If I designate --version as an implicit flag, then I also get an --no-version flag in the help section which is confusing to say the least.
• How do I get the value of --config-file in the yaml_file option of the YamlConfigSettingsSource? Is this supported?
• How can I make some options CLI only? Can I make some config file only?

[hramezani]

If I designate --version as an implicit flag, then I also get an --no-version flag in the help section which is confusing to say the least.

@kschwab is it possible?

How do I get the value of --config-file in the yaml_file option of the YamlConfigSettingsSource? Is this supported?

It is not possible right now. you have to do some hacky workaround. take a look at #259

How can I make some options CLI only? Can I make some config file only?

No, if you define a field in a settings model, then pydantic-settings tries to collect value for it from all the available settings sources. So, probably you can define them in a separate settings model and limit the settings model to only use cli or file.

[kschwab]

@hramezani, it is possible, we would need to add another annotation to denote creating a boolean flag without --no-. Currently, this is standard behavior for python versions < 3.9 due to argparse limitation. For python >= 3.9, it always generates with the --no-. It is relatively small change, let me know if you would like me to proceed forward with PR.

[hramezani]

@kschwab Thanks for your response. if it is not possible to remove the --no- in argparse, It is better not to support it.

[MartenBE]

Thank you all for the input. I have decided to go with OmegaConf instead as this gives me more flexibility. I'll close this issue.

[kschwab]

@hramezani, just for future clarity in case it comes up again, argparse supports both but uses different "actions". For just a constant flag, it uses the "store_true/store_false" actions, and for the "--with,--no-with" it uses the "BooleanOptionalAction" (which was added in python 3.9). Therefore, we just need to expose the constant actions explicitly, it is a small task if needed in the future.

[hramezani]

Thanks @kschwab for clarification.
Ok, we can consider this