Pydantic Settings YAML

0.2.0 verified Mon Apr 27 auth: no python

Adds YAML support to pydantic-settings, enabling loading settings from YAML files via the BaseSettings model. Currently at version 0.2.0, requires Python >=3.8. Released irregularly as a small utility package.

pip install pydantic-settings-yaml

Common errors

error ImportError: cannot import name 'YamlSettingsSource' from 'pydantic_settings_yaml' ↓

cause The class was renamed to YamlConfigSettingsSource in v0.2.0.

fix

Use: from pydantic_settings_yaml import YamlConfigSettingsSource

error pydantic_settings.sources.SettingsError: Unknown settings source type: <class '...'> ↓

cause The custom settings source is not correctly registered or imported.

fix

Ensure YamlConfigSettingsSource is imported and passed to settings_customise_sources if needed.

Warnings

breaking In version 0.2.0, the class was renamed from YamlSettingsSource to YamlConfigSettingsSource. Existing code using the old name will break. ↓

fix Update imports: from pydantic_settings_yaml import YamlConfigSettingsSource

gotcha The YAML file is loaded only during initialization. If the file changes later, the settings are not refreshed automatically. ↓

fix Call Settings() again or implement a reload mechanism.

gotcha Settings are case-sensitive. YAML keys must exactly match the model field names. ↓

fix Ensure field names in model and YAML keys match exactly.

Imports

YamlConfigSettingsSource
wrong
```
from pydantic_settings_yaml import YamlSettingsSource
```
correct
```
from pydantic_settings_yaml import YamlConfigSettingsSource
```
Old name before 0.2.0 was 'YamlSettingsSource'; renamed to 'YamlConfigSettingsSource' in 0.2.0.

Quickstart

Define a Pydantic model with a YAML configuration source. The YAML file 'config.yaml' can contain keys like `app_name` and `debug`.

from pydantic_settings import BaseSettings, SettingsConfigDict
from pydantic_settings_yaml import YamlConfigSettingsSource

class Settings(BaseSettings):
    model_config = SettingsConfigDict(yaml_file='config.yaml')

    app_name: str = "MyApp"
    debug: bool = False

settings = Settings()
print(settings.app_name)
print(settings.debug)