Use config values as default in PydanticBaseEnvSettingsSource.__init__

[hramezani]

Fixes #98

Selected Reviewer: @samuelcolvin

[hramezani]

please review

[Viicos]

Thanks!

I don't think this addresses the issue unfortunately. Here's a MRE of what should be expected:

class CustomEnvSettingsSource(EnvSettingsSource):
    pass

class Settings(BaseSettings):
    foo: 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, ...]:
        custom_env_settings = CustomEnvSettingsSource(settings_cls)  # CustomEnvSettingsSource should be able to use config values either from `model_config` or values given at instantiation
        return init_settings, custom_env_settings, dotenv_settings, file_secret_settings

os.environ["prefix_foo"] = "test_foo"

s = Settings(_env_prefix="prefix_")
assert s.foo == "test_foo"

What the added tests show is that CustomEnvSettingsSource is able to read values from model_config, but not from instantation arguments 😕

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (107e8de) 97.42% compared to head (8b6daf5) 97.42%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #100   +/-   ##
=======================================
  Coverage   97.42%   97.42%           
=======================================
  Files           5        5           
  Lines         311      311           
  Branches       68       68           
=======================================
  Hits          303      303           
  Misses          6        6           
  Partials        2        2           

Impacted Files	Coverage Δ
pydantic_settings/sources.py	97.70% <100.00%> (ø)

☔ View full report in Codecov by Sentry.
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[hramezani]

Thanks!

I don't think this addresses the issue unfortunately. Here's a MRE of what should be expected:

class CustomEnvSettingsSource(EnvSettingsSource):
    pass

class Settings(BaseSettings):
    foo: 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, ...]:
        custom_env_settings = CustomEnvSettingsSource(settings_cls)  # CustomEnvSettingsSource should be able to use config values either from `model_config` or values given at instantiation
        return init_settings, custom_env_settings, dotenv_settings, file_secret_settings

os.environ["prefix_foo"] = "test_foo"

s = Settings(_env_prefix="prefix_")
assert s.foo == "test_foo"

What the added tests show is that CustomEnvSettingsSource is able to read values from model_config, but not from instantation arguments 😕

You can pass env_prefix in custom source initialization.

custom_env_settings = CustomEnvSettingsSource(settings_cls, env_prefix="prefix_")

or define it in config as I shared an example in the issue

[Viicos]

You can pass env_prefix in custom source initialization.

custom_env_settings = CustomEnvSettingsSource(settings_cls, env_prefix="prefix_")

or define it in config as I shared an example in the #98 (comment)

But the env_prefix is then hardcoded into the code, and not configurable from instantiation arguments

I understand the MRE I gave here can't be supported, as trying to support it might lead to too many breaking changes.
I can still offer a PR and see if it's worth it 😉

[hramezani]

@Viicos _env_prefix and the other instantiation arguments are for settings class init not the source class init.

If you define a custom source, you need to initialize it in settings_customise_sources and then you can pass args there.

I understand the MRE I gave #100 (review) can't be supported, as trying to support it might lead to too many breaking changes.
I can still offer a PR and see if it's worth it 😉

I would be happy to take a look at that. we can merge it if it is an easy one. because as I mentioned above, you can initialize a custom source in settings_customise_sources and it is not block you.

[Kludex]

I merged without seeing the messages above, sorry. Hope is cool.

[Viicos]

I merged without seeing the messages above, sorry. Hope is cool.

Yes this is still an improvement, thanks for merging