Tweak sources to have case_sensitive and env_prefix usable as args (#76)

Co-authored-by: Hasan Ramezani <[email protected]>

Author: Viicos

docs/index.md

@@ -90,7 +90,8 @@ print(Settings().model_dump())
 
 By default, the environment variable name is the same as the field name.
 
-You can change the prefix for all environment variables by setting the `env_prefix` config setting:
+You can change the prefix for all environment variables by setting the `env_prefix` config setting,
+or via the `_env_prefix` keyword argument on instantiation:
 
 ```py
 from pydantic_settings import BaseSettings, SettingsConfigDict
@@ -135,6 +136,8 @@ so in this example `redis_host` could only be modified via `export redis_host`.
 all upper-case, you should name attribute all upper-case too. You can still name environment variables anything
 you like through `Field(validation_alias=...)`.
 
+Case-sensitivity can also be set via the `_case_sensitive` keyword argument on instantiation.
+
 In case of nested models, the `case_sensitive` setting will be applied to all nested models.
 
 ```py
@@ -316,7 +319,7 @@ in the `BaseSettings` class:
 
 ```py test="skip" lint="skip"
 class Settings(BaseSettings):
-    model_config = SettingsConfigDict(env_file='.env', env_file_encoding = 'utf-8')
+    model_config = SettingsConfigDict(env_file='.env', env_file_encoding='utf-8')
 ```
 
 2. Instantiating the `BaseSettings` derived class with the `_env_file` keyword argument

pydantic_settings/main.py

@@ -38,14 +38,18 @@ class BaseSettings(BaseModel):
     All the bellow attributes can be set via `model_config`.
 
     Args:
+        _case_sensitive: Whether environment variables names should be read with case-sensitivity. Defaults to `None`.
+        _env_prefix: Prefix for all environment variables. Defaults to `None`.
         _env_file: The env file(s) to load settings values from. Defaults to `Path('')`.
-        _env_file_encoding: The env file encoding. e.g. `'latin-1'`. Defaults to `None`.
+        _env_file_encoding: The env file encoding, e.g. `'latin-1'`. Defaults to `None`.
         _env_nested_delimiter: The nested env values delimiter. Defaults to `None`.
         _secrets_dir: The secret files directory. Defaults to `None`.
     """
 
     def __init__(
         __pydantic_self__,
+        _case_sensitive: bool | None = None,
+        _env_prefix: str | None = None,
         _env_file: DotenvType | None = env_file_sentinel,
         _env_file_encoding: str | None = None,
         _env_nested_delimiter: str | None = None,
@@ -56,6 +60,8 @@ def __init__(
         super().__init__(
             **__pydantic_self__._settings_build_values(
                 values,
+                _case_sensitive=_case_sensitive,
+                _env_prefix=_env_prefix,
                 _env_file=_env_file,
                 _env_file_encoding=_env_file_encoding,
                 _env_nested_delimiter=_env_nested_delimiter,
@@ -90,38 +96,46 @@ def settings_customise_sources(
     def _settings_build_values(
         self,
         init_kwargs: dict[str, Any],
+        _case_sensitive: bool | None = None,
+        _env_prefix: str | None = None,
         _env_file: DotenvType | None = None,
         _env_file_encoding: str | None = None,
         _env_nested_delimiter: str | None = None,
         _secrets_dir: str | Path | None = None,
     ) -> dict[str, Any]:
+        # Determine settings config values
+        case_sensitive = _case_sensitive if _case_sensitive is not None else self.model_config.get('case_sensitive')
+        env_prefix = _env_prefix if _env_prefix is not None else self.model_config.get('env_prefix')
+        env_file = _env_file if _env_file != env_file_sentinel else self.model_config.get('env_file')
+        env_file_encoding = (
+            _env_file_encoding if _env_file_encoding is not None else self.model_config.get('env_file_encoding')
+        )
+        env_nested_delimiter = (
+            _env_nested_delimiter
+            if _env_nested_delimiter is not None
+            else self.model_config.get('env_nested_delimiter')
+        )
+        secrets_dir = _secrets_dir if _secrets_dir is not None else self.model_config.get('secrets_dir')
+
         # Configure built-in sources
         init_settings = InitSettingsSource(self.__class__, init_kwargs=init_kwargs)
         env_settings = EnvSettingsSource(
             self.__class__,
-            env_nested_delimiter=(
-                _env_nested_delimiter
-                if _env_nested_delimiter is not None
-                else self.model_config.get('env_nested_delimiter')
-            ),
-            env_prefix_len=len(self.model_config.get('env_prefix', '')),
+            case_sensitive=case_sensitive,
+            env_prefix=env_prefix,
+            env_nested_delimiter=env_nested_delimiter,
         )
         dotenv_settings = DotEnvSettingsSource(
             self.__class__,
-            env_file=(_env_file if _env_file != env_file_sentinel else self.model_config.get('env_file')),
-            env_file_encoding=(
-                _env_file_encoding if _env_file_encoding is not None else self.model_config.get('env_file_encoding')
-            ),
-            env_nested_delimiter=(
-                _env_nested_delimiter
-                if _env_nested_delimiter is not None
-                else self.model_config.get('env_nested_delimiter')
-            ),
-            env_prefix_len=len(self.model_config.get('env_prefix', '')),
+            env_file=env_file,
+            env_file_encoding=env_file_encoding,
+            case_sensitive=case_sensitive,
+            env_prefix=env_prefix,
+            env_nested_delimiter=env_nested_delimiter,
         )
 
         file_secret_settings = SecretsSettingsSource(
-            self.__class__, secrets_dir=_secrets_dir or self.model_config.get('secrets_dir')
+            self.__class__, secrets_dir=secrets_dir, case_sensitive=case_sensitive, env_prefix=env_prefix
         )
         # Provide a hook to set built-in sources priority and add / remove sources
         sources = self.settings_customise_sources(

pydantic_settings/sources.py

@@ -108,8 +108,15 @@ def __repr__(self) -> str:
 
 
 class PydanticBaseEnvSettingsSource(PydanticBaseSettingsSource):
+    def __init__(
+        self, settings_cls: type[BaseSettings], case_sensitive: bool | None = None, env_prefix: str | None = None
+    ) -> None:
+        super().__init__(settings_cls)
+        self.case_sensitive = case_sensitive if case_sensitive is not None else False
+        self.env_prefix = env_prefix if env_prefix is not None else ''
+
     def _apply_case_sensitive(self, value: str) -> str:
-        return value.lower() if not self.config.get('case_sensitive') else value
+        return value.lower() if not self.case_sensitive else value
 
     def _extract_field_info(self, field: FieldInfo, field_name: str) -> list[tuple[str, str, bool]]:
         """
@@ -147,9 +154,7 @@ def _extract_field_info(self, field: FieldInfo, field_name: str) -> list[tuple[s
             else:  # string validation alias
                 field_info.append((v_alias, self._apply_case_sensitive(v_alias), False))
         else:
-            field_info.append(
-                (field_name, self._apply_case_sensitive(self.config.get('env_prefix', '') + field_name), False)
-            )
+            field_info.append((field_name, self._apply_case_sensitive(self.env_prefix + field_name), False))
 
         return field_info
 
@@ -231,7 +236,7 @@ def __call__(self) -> dict[str, Any]:
                 ) from e
 
             if field_value is not None:
-                if not self.config.get('case_sensitive', False) and lenient_issubclass(field.annotation, BaseModel):
+                if not self.case_sensitive and lenient_issubclass(field.annotation, BaseModel):
                     data[field_key] = self._replace_field_names_case_insensitively(field, field_value)
                 else:
                     data[field_key] = field_value
@@ -244,9 +249,15 @@ class SecretsSettingsSource(PydanticBaseEnvSettingsSource):
     Source class for loading settings values from secret files.
     """
 
-    def __init__(self, settings_cls: type[BaseSettings], secrets_dir: str | Path | None):
+    def __init__(
+        self,
+        settings_cls: type[BaseSettings],
+        secrets_dir: str | Path | None,
+        case_sensitive: bool | None = None,
+        env_prefix: str | None = None,
+    ) -> None:
+        super().__init__(settings_cls, case_sensitive, env_prefix)
         self.secrets_dir = secrets_dir
-        super().__init__(settings_cls)
 
     def __call__(self) -> dict[str, Any]:
         """
@@ -302,9 +313,7 @@ def get_field_value(self, field: FieldInfo, field_name: str) -> tuple[Any, str,
         """
 
         for field_key, env_name, value_is_complex in self._extract_field_info(field, field_name):
-            path = self.find_case_path(
-                self.secrets_path, env_name, self.settings_cls.model_config.get('case_sensitive', False)
-            )
+            path = self.find_case_path(self.secrets_path, env_name, self.case_sensitive)
             if not path:
                 # path does not exist, we curently don't return a warning for this
                 continue
@@ -331,18 +340,18 @@ class EnvSettingsSource(PydanticBaseEnvSettingsSource):
     def __init__(
         self,
         settings_cls: type[BaseSettings],
+        case_sensitive: bool | None = None,
+        env_prefix: str | None = None,
         env_nested_delimiter: str | None = None,
-        env_prefix_len: int = 0,
-    ):
-        super().__init__(settings_cls)
-
-        self.env_nested_delimiter: str | None = env_nested_delimiter
-        self.env_prefix_len: int = env_prefix_len
+    ) -> None:
+        super().__init__(settings_cls, case_sensitive, env_prefix)
+        self.env_nested_delimiter = env_nested_delimiter
+        self.env_prefix_len = len(self.env_prefix)
 
-        self.env_vars: Mapping[str, str | None] = self._load_env_vars()
+        self.env_vars = self._load_env_vars()
 
     def _load_env_vars(self) -> Mapping[str, str | None]:
-        if self.settings_cls.model_config.get('case_sensitive'):
+        if self.case_sensitive:
             return os.environ
         return {k.lower(): v for k, v in os.environ.items()}
 
@@ -521,16 +530,16 @@ def __init__(
         settings_cls: type[BaseSettings],
         env_file: DotenvType | None,
         env_file_encoding: str | None,
+        case_sensitive: bool | None = None,
+        env_prefix: str | None = None,
         env_nested_delimiter: str | None = None,
-        env_prefix_len: int = 0,
-    ):
-        self.env_file: DotenvType | None = env_file
-        self.env_file_encoding: str | None = env_file_encoding
-
-        super().__init__(settings_cls, env_nested_delimiter, env_prefix_len)
+    ) -> None:
+        self.env_file = env_file
+        self.env_file_encoding = env_file_encoding
+        super().__init__(settings_cls, case_sensitive, env_prefix, env_nested_delimiter)
 
     def _load_env_vars(self) -> Mapping[str, str | None]:
-        return self._read_env_files(self.settings_cls.model_config.get('case_sensitive', False))
+        return self._read_env_files(self.case_sensitive)
 
     def _read_env_files(self, case_sensitive: bool) -> Mapping[str, str | None]:
         env_files = self.env_file
@@ -554,7 +563,7 @@ def __call__(self) -> dict[str, Any]:
         data: dict[str, Any] = super().__call__()
 
         data_lower_keys: list[str] = []
-        if not self.settings_cls.model_config.get('case_sensitive', False):
+        if not self.case_sensitive:
             data_lower_keys = [x.lower() for x in data.keys()]
 
         # As `extra` config is allowed in dotenv settings source, We have to

tests/test_settings.py

@@ -1630,3 +1630,25 @@ class Model(BaseSettings):
 
         class Model1(BaseSettings):
             settings_prefixed_field: str
+
+
+def test_case_sensitive_from_args(monkeypatch):
+    class Settings(BaseSettings):
+        foo: str
+
+    # Need to patch os.environ to get build to work on Windows, where os.environ is case insensitive
+    monkeypatch.setattr(os, 'environ', value={'Foo': 'foo'})
+    with pytest.raises(ValidationError) as exc_info:
+        Settings(_case_sensitive=True)
+    assert exc_info.value.errors(include_url=False) == [
+        {'type': 'missing', 'loc': ('foo',), 'msg': 'Field required', 'input': {}}
+    ]
+
+
+def test_env_prefix_from_args(env):
+    class Settings(BaseSettings):
+        apple: str
+
+    env.set('foobar_apple', 'has_prefix')
+    s = Settings(_env_prefix='foobar_')
+    assert s.apple == 'has_prefix'