Fix PathType typing in case of sequence

[just-maiyak]

Fixes #401

[hramezani]

I just fixed the syntax error to let the CI run

[just-maiyak]

Perfect thank you so much, I amended without staging the changes and after that I didn't have my laptop on hand 😅

[just-maiyak]

I fixed the CI, there were still a couple of unused imports. It should be good to merge :)

[hramezani]

Thanks @just-maiyak for updating this PR.

Could you provide a simple example that has mypy error? I am going to test the error and the fix?

Thanks!

[just-maiyak]

Sure, if you run mypy on this file :

from pydantic_settings import BaseSettings, YamlConfigSettingsSource


class Settings(BaseSettings):
    config_files = ["config.yaml"]
    model_config = YamlConfigSettingsSource(BaseSettings, yaml_file=config_files)

It will fail with the error I reported in #401.

[hramezani]

Thanks @just-maiyak for providing the example.

The model that you provided looks weird to me. Could you explain why you are using YamlConfigSettingsSource in the model_config?

[just-maiyak]

I'm trying to read settings from a list of yaml files (just like we would from a .env file). I'm following the docs right here : Other Settings Source.

[hramezani]

But this should be like the first example in the page:

from typing import Tuple, Type

from pydantic import BaseModel

from pydantic_settings import (
    BaseSettings,
    PydanticBaseSettingsSource,
    SettingsConfigDict,
    TomlConfigSettingsSource,
)


class Nested(BaseModel):
    nested_field: str


class Settings(BaseSettings):
    foobar: str
    nested: Nested
    model_config = SettingsConfigDict(toml_file='config.toml')

    @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 (TomlConfigSettingsSource(settings_cls),)

You only need to change the TomlConfigSettingsSource with YamlConfigSettingsSource

[just-maiyak]

Alright, it's not very clear from the docs that you have to keep settings_customize_sources. It's also not so clear how SettingsConfigDict works. Is the latter built from calling settings_customize_sources ?
Edit: I'll close this PR because I using settings_customize_sources solved my problem, but I do think the docs need to be more explicit. Should I open another issue ?

[hramezani]

Alright, it's not very clear from the docs that you have to keep settings_customize_sources

This is because yaml settings source is not part of the default settings sources and you need to somehow override the default behavior to enable this source. we decided to use this approach to prevent breaking change in V2.
Here is the doc.

BTW, any improvement on docs is welcome. feel free to create a PR if you want. You don't need to create a new issue.

Thanks!

[just-maiyak]

I'll work on a docs contribution :) Thanks for helping out !

[just-maiyak]

Sorry for being so persistent ... I'm reopening this again because I still thing the issue is happening in the case I start from the sample you provide and parametrize the yaml_file like so :

from typing import Tuple, Type

from pydantic import BaseModel

from pydantic_settings import (
    BaseSettings,
    PydanticBaseSettingsSource,
    SettingsConfigDict,
    TomlConfigSettingsSource,
)


class Nested(BaseModel):
    nested_field: str


class Settings(BaseSettings):
    foobar: str
    nested: Nested

    config_files: list[str] = ["config.yaml"] # This might be the return of a funtion or initialized in __init__
    model_config = SettingsConfigDict(toml_file=config_files)

    @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 (TomlConfigSettingsSource(settings_cls),)

This produces yet again the same error as before. Should this be done in another way ?

[hramezani]

I think the config_files: list[str] = ["config.yaml"] is not the correct way. You probably did it like this because the config file name is not specified and you want to pass it when you initialize the model.

There is an issue for this problem #259
I am going to prepare a PR for this issue but before that probably you can use one of the workaround suggested in the issue.

[just-maiyak]

That's my case indeed, want to provide additional files at runtime. Unfortunately, I still have the same typing problem even with the workaround as soon as I wrap the settings filenames in a list.

I still think the Sequence type is more appropriate if write operations to that variable are not possible (which I think is the case because it seems we only construct settings once as soon as we read that yaml_config parameter).

What also works is to explicitly type whatever we're passing as list[Path | str] but that introduces unnecessary noise imo.