Add support for toml #210

pydantic_settings/__init__.py

@@ -5,6 +5,7 @@
     InitSettingsSource,
     PydanticBaseSettingsSource,
     SecretsSettingsSource,
+    TomlSettingsSource,
 )
 from .version import VERSION
 
@@ -16,6 +17,7 @@
     'PydanticBaseSettingsSource',
     'SecretsSettingsSource',
     'SettingsConfigDict',
+    'TomlSettingsSource',
     '__version__',
 )
 

pydantic_settings/sources.py

@@ -18,11 +18,19 @@
 
 from pydantic_settings.utils import path_type_label
 
+try:
+    import tomllib  # type:ignore
+except ImportError:
+    import tomli as tomllib
+
 if TYPE_CHECKING:
     from pydantic_settings.main import BaseSettings
 
 
 DotenvType = Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]
+PathType = Union[Path, str, List[Union[Path, str]], Tuple[Union[Path, str], ...]]
+
+DEFAULT_PATH: PathType = Path('')
 
 # This is used as default value for `_env_file` in the `BaseSettings` class and
 # `env_file` in `DotEnvSettingsSource` so the default can be distinguished from `None`.
@@ -716,3 +724,42 @@ def _annotation_is_complex_inner(annotation: type[Any] | None) -> bool:
     return lenient_issubclass(annotation, (BaseModel, Mapping, Sequence, tuple, set, frozenset, deque)) or is_dataclass(
         annotation
     )
+
+
+class TomlSettingsSource(InitSettingsSource):
+    """
+    Source class for loading values provided through TOML files.
+    """
+
+    def __init__(self, settings_cls: type[BaseSettings], toml_file: PathType | None = DEFAULT_PATH):
+        self.toml_file = toml_file if toml_file != DEFAULT_PATH else settings_cls.model_config.get('toml_file')
+        self.toml_data = self._load_toml_data()
+        super().__init__(settings_cls, self.toml_data)
+
+    def _load_toml_data(self) -> dict[str, Any | None]:
+        return self._read_toml_files()
+
+    def _read_toml_files(self) -> dict[str, Any | None]:
+        toml_files = self.toml_file
+        if toml_files is None:
+            return {}
+        if isinstance(toml_files, (str, os.PathLike)):
+            toml_files = [toml_files]
+        toml_vars: dict[str, Any | None] = {}
+        for toml_file in toml_files:  # type: ignore[attr-defined]
+            toml_path = Path(toml_file).expanduser()
+            if toml_path.is_file():
+                toml_vars.update(self._read_toml_file(toml_path))
+        return toml_vars
+
+    def _read_toml_file(self, toml_path: Path) -> dict[str, Any | None]:
+        toml_data = {}
+        with open(toml_path, mode='rb') as fp:
+            try:
+                toml_data = tomllib.load(fp)
+            except Exception as e:
+                warnings.warn(f'Failed to load "{toml_path} - {e}"')
+        return toml_data
+
+    def __repr__(self) -> str:
+        return f'TomlSettingsSource(toml_file={self.toml_file!r})'

pyproject.toml

@@ -42,6 +42,7 @@ requires-python = '>=3.8'
 dependencies = [
     'pydantic>=2.3.0',
     'python-dotenv>=0.21.0',
+    'tomli>=1.1.0; python_version < "3.11"',
 ]
 dynamic = ['version']
 

tests/test_settings.py

@@ -33,6 +33,7 @@
     PydanticBaseSettingsSource,
     SecretsSettingsSource,
     SettingsConfigDict,
+    TomlSettingsSource,
 )
 from pydantic_settings.sources import SettingsError, read_env_file
 
@@ -1910,8 +1911,41 @@ def test_dotenv_optional_json_field(tmp_path):
 
     class Settings(BaseSettings):
         model_config = SettingsConfigDict(env_file=p)
-
         data: Optional[Json[Dict[str, str]]] = Field(default=None)
 
     s = Settings()
     assert s.data == {'foo': 'bar'}
+
+
+def test_toml_file(tmp_path):
+    p = tmp_path / 'settings.toml'
+    toml_content = '''
+foobar = "foobarval"
+
+[foo]
+bar = "nested-foo-bar"'''
+    p.write_text(toml_content)
+
+    class Settings(BaseSettings):
+        model_config = SettingsConfigDict(toml_file=p)
+
+        class Foo(BaseSettings):
+            bar: str
+
+        foobar: str
+        foo: Foo
+
+        @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 init_settings, env_settings, dotenv_settings, file_secret_settings, TomlSettingsSource(settings_cls)
+
+    s = Settings()
+    assert s.foobar == 'foobarval'
+    assert s.foo.bar == 'nested-foo-bar'