Python pydantic.BaseSettings() Examples

def test_env_file_example(tmp_path):
    p = tmp_path / '.env'
    p.write_text(
        """\
# ignore comment
ENVIRONMENT="production"
REDIS_ADDRESS=localhost:6379
MEANING_OF_LIFE=42
MY_VAR='Hello world'
"""
    )

    class Settings(BaseSettings):
        environment: str
        redis_address: str
        meaning_of_life: int
        my_var: str

    s = Settings(_env_file=str(p))
    assert s.dict() == {
        'environment': 'production',
        'redis_address': 'localhost:6379',
        'meaning_of_life': 42,
        'my_var': 'Hello world',
    } 

def test_env_inheritance(env):
    class SettingsParent(BaseSettings):
        foobar: str = 'parent default'

        class Config:
            fields = {'foobar': {'env': 'different'}}

    class SettingsChild(SettingsParent):
        foobar: str = 'child default'

    assert SettingsParent().foobar == 'parent default'
    assert SettingsParent(foobar='abc').foobar == 'abc'

    assert SettingsChild().foobar == 'child default'
    assert SettingsChild(foobar='abc').foobar == 'abc'
    env.set('different', 'env value')
    assert SettingsParent().foobar == 'env value'
    assert SettingsParent(foobar='abc').foobar == 'abc'
    assert SettingsChild().foobar == 'env value'
    assert SettingsChild(foobar='abc').foobar == 'abc' 

def test_env_inheritance_field(env):
    class SettingsParent(BaseSettings):
        foobar: str = Field('parent default', env='foobar_env')

    class SettingsChild(SettingsParent):
        foobar: str = 'child default'

    assert SettingsParent().foobar == 'parent default'
    assert SettingsParent(foobar='abc').foobar == 'abc'

    assert SettingsChild().foobar == 'child default'
    assert SettingsChild(foobar='abc').foobar == 'abc'
    env.set('foobar_env', 'env value')
    assert SettingsParent().foobar == 'env value'
    assert SettingsParent(foobar='abc').foobar == 'abc'
    assert SettingsChild().foobar == 'child default'
    assert SettingsChild(foobar='abc').foobar == 'abc' 

def test_env_file_export(env, tmp_path):
    p = tmp_path / '.env'
    p.write_text(
        """\
export A='good string'
export B=better-string
export C="best string"
"""
    )

    class Settings(BaseSettings):
        a: str
        b: str
        c: str

        class Config:
            env_file = p

    env.set('A', 'overridden var')

    s = Settings()
    assert s.a == 'overridden var'
    assert s.b == 'better-string'
    assert s.c == 'best string' 

def test_env_file_config_case_sensitive(tmp_path):
    p = tmp_path / '.env'
    p.write_text(test_env_file)

    class Settings(BaseSettings):
        a: str
        b: str
        c: str

        class Config:
            env_file = p
            case_sensitive = True

    with pytest.raises(ValidationError) as exc_info:
        Settings()
    assert exc_info.value.errors() == [{'loc': ('a',), 'msg': 'field required', 'type': 'value_error.missing'}] 

def test_env_file_config(env, tmp_path):
    p = tmp_path / '.env'
    p.write_text(test_env_file)

    class Settings(BaseSettings):
        a: str
        b: str
        c: str

        class Config:
            env_file = p

    env.set('A', 'overridden var')

    s = Settings()
    assert s.a == 'overridden var'
    assert s.b == 'better string'
    assert s.c == 'best string' 

def test_config_file_settings_nornir(env):
    """
    See https://github.com/samuelcolvin/pydantic/pull/341#issuecomment-450378771
    """

    class Settings(BaseSettings):
        a: str
        b: str
        c: str

        def _build_values(self, init_kwargs, _env_file, _env_file_encoding):
            config_settings = init_kwargs.pop('__config_settings__')
            return {**config_settings, **init_kwargs, **self._build_environ()}

    env.set('C', 'env setting c')

    config = {'a': 'config a', 'b': 'config b', 'c': 'config c'}
    s = Settings(__config_settings__=config, b='argument b', c='argument c')
    assert s.a == 'config a'
    assert s.b == 'argument b'
    assert s.c == 'env setting c' 

def test_case_insensitive(monkeypatch):
    class Settings1(BaseSettings):
        foo: str

    with pytest.warns(DeprecationWarning, match='Settings2: "case_insensitive" is deprecated on BaseSettings'):

        class Settings2(BaseSettings):
            foo: str

            class Config:
                case_insensitive = False

    assert Settings1.__config__.case_sensitive is False
    assert Settings2.__config__.case_sensitive is True 

def test_frozenset(env):
    class Settings(BaseSettings):
        foo: str = 'default foo'

        class Config:
            fields = {'foo': {'env': frozenset(['foo_a', 'foo_b'])}}

    assert Settings.__fields__['foo'].field_info.extra['env_names'] == frozenset({'foo_a', 'foo_b'})

    assert Settings().dict() == {'foo': 'default foo'}
    env.set('foo_a', 'x')
    assert Settings().dict() == {'foo': 'x'} 

def test_prefix_on_parent(env):
    class MyBaseSettings(BaseSettings):
        var: str = 'old'

    class MySubSettings(MyBaseSettings):
        class Config:
            env_prefix = 'PREFIX_'

    assert MyBaseSettings().dict() == {'var': 'old'}
    assert MySubSettings().dict() == {'var': 'old'}
    env.set('PREFIX_VAR', 'new')
    assert MyBaseSettings().dict() == {'var': 'old'}
    assert MySubSettings().dict() == {'var': 'new'} 

def test_alias_set(env):
    class Settings(BaseSettings):
        foo: str = 'default foo'
        bar: str = 'bar default'

        class Config:
            fields = {'foo': {'env': 'foo_env'}}

    assert Settings.__fields__['bar'].name == 'bar'
    assert Settings.__fields__['bar'].alias == 'bar'
    assert Settings.__fields__['foo'].name == 'foo'
    assert Settings.__fields__['foo'].alias == 'foo'

    class SubSettings(Settings):
        spam: str = 'spam default'

    assert SubSettings.__fields__['bar'].name == 'bar'
    assert SubSettings.__fields__['bar'].alias == 'bar'
    assert SubSettings.__fields__['foo'].name == 'foo'
    assert SubSettings.__fields__['foo'].alias == 'foo'

    assert SubSettings().dict() == {'foo': 'default foo', 'bar': 'bar default', 'spam': 'spam default'}
    env.set('foo_env', 'fff')
    assert SubSettings().dict() == {'foo': 'fff', 'bar': 'bar default', 'spam': 'spam default'}
    env.set('bar', 'bbb')
    assert SubSettings().dict() == {'foo': 'fff', 'bar': 'bbb', 'spam': 'spam default'}
    env.set('spam', 'sss')
    assert SubSettings().dict() == {'foo': 'fff', 'bar': 'bbb', 'spam': 'sss'} 

def test_dotenv_not_installed(tmp_path):
    p = tmp_path / '.env'
    p.write_text('a=b')

    class Settings(BaseSettings):
        a: str

    with pytest.raises(ImportError, match=r'^python-dotenv is not installed, run `pip install pydantic\[dotenv\]`$'):
        Settings(_env_file=p) 

def test_env_file_not_a_file(env):
    class Settings(BaseSettings):
        a: str = None

    env.set('A', 'ignore non-file')
    s = Settings(_env_file='tests/')
    assert s.a == 'ignore non-file' 

def test_env_file_override_none(tmp_path):
    p = tmp_path / '.env'
    p.write_text(test_env_file)

    class Settings(BaseSettings):
        a: str = None

        class Config:
            env_file = p

    s = Settings(_env_file=None)
    assert s.a is None 

def test_env_file_override_file(tmp_path):
    p1 = tmp_path / '.env'
    p1.write_text(test_env_file)
    p2 = tmp_path / '.env.prod'
    p2.write_text('A="new string"')

    class Settings(BaseSettings):
        a: str

        class Config:
            env_file = str(p1)

    s = Settings(_env_file=p2)
    assert s.a == 'new string' 

def test_env_file_none(tmp_path):
    p = tmp_path / '.env'
    p.write_text('a')

    class Settings(BaseSettings):
        a: str = 'xxx'

    s = Settings(_env_file=p)
    assert s.a == 'xxx' 

def test_env_takes_precedence(env):
    class Settings(BaseSettings):
        foo: int
        bar: str

        def _build_values(self, init_kwargs, _env_file, _env_file_encoding):
            return {**init_kwargs, **self._build_environ()}

    env.set('BAR', 'env setting')

    s = Settings(foo='123', bar='argument')
    assert s.foo == 123
    assert s.bar == 'env setting' 

def is_pydantic(test_object):
    try:
        instance = isinstance(test_object, BaseSettings) or isinstance(test_object, BaseModel)
    except TypeError:
        instance = False
    try:
        subclass = issubclass(test_object, BaseSettings) or issubclass(test_object, BaseModel)
    except TypeError:
        subclass = False
    return instance or subclass 

def test_case_sensitive(monkeypatch):
    class Settings(BaseSettings):
        foo: str

        class Config:
            case_sensitive = True

    # 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()
    assert exc_info.value.errors() == [{'loc': ('foo',), 'msg': 'field required', 'type': 'value_error.missing'}] 

def test_aliases_no_warning(env):
    class Settings(BaseSettings):
        foobar: str = 'default value'

        class Config:
            fields = {'foobar': {'alias': 'foobar_alias', 'env': 'foobar_env'}}

    assert Settings().foobar == 'default value'
    assert Settings(foobar_alias='42').foobar == '42'
    env.set('foobar_alias', 'xxx')
    assert Settings().foobar == 'default value'
    env.set('foobar_env', 'xxx')
    assert Settings().foobar == 'xxx'
    assert Settings(foobar_alias='42').foobar == '42' 

def test_aliases_warning(env):
    with pytest.warns(FutureWarning, match='aliases are no longer used by BaseSettings'):

        class Settings(BaseSettings):
            foobar: str = 'default value'

            class Config:
                fields = {'foobar': 'foobar_alias'}

    assert Settings().foobar == 'default value'
    env.set('foobar_alias', 'xxx')
    assert Settings().foobar == 'default value'
    assert Settings(foobar_alias='42').foobar == '42' 

def test_env_field(env):
    with pytest.raises(TypeError, match=r'invalid field env: 123 \(int\); should be string, list or set'):

        class Settings(BaseSettings):
            foobar: str = Field(..., env=123) 

def test_env_list_last(env):
    class Settings(BaseSettings):
        foobar: str

        class Config:
            fields = {'foobar': {'env': ['different2']}}

    env.set('different1', 'value 1')
    env.set('different2', 'value 2')
    s = Settings()
    assert s.foobar == 'value 2'
    assert Settings(foobar='abc').foobar == 'abc' 

def test_env_list_field(env):
    class Settings(BaseSettings):
        foobar: str = Field(..., env='foobar_env_name')

    env.set('FOOBAR_ENV_NAME', 'env value')
    s = Settings()
    assert s.foobar == 'env value' 

def test_env_list(env):
    class Settings(BaseSettings):
        foobar: str

        class Config:
            fields = {'foobar': {'env': ['different1', 'different2']}}

    env.set('different1', 'value 1')
    env.set('different2', 'value 2')
    s = Settings()
    assert s.foobar == 'value 1' 

def test_non_class(env):
    class Settings(BaseSettings):
        foobar: NoneStr

    env.set('FOOBAR', 'xxx')
    s = Settings()
    assert s.foobar == 'xxx' 

def test_required_sub_model(env):
    class Settings(BaseSettings):
        foobar: DateModel

    with pytest.raises(ValidationError):
        Settings()
    env.set('FOOBAR', '{"pips": "TRUE"}')
    s = Settings()
    assert s.foobar.pips is True 

def test_nested_env_with_dict(env):
    class Settings(BaseSettings):
        top: Dict[str, str]

    with pytest.raises(ValidationError):
        Settings()
    env.set('top', '{"banana": "secret_value"}')
    s = Settings(top={'apple': 'value'})
    assert s.top == {'apple': 'value', 'banana': 'secret_value'} 

def test_nested_env_with_basemodel(env):
    class TopValue(BaseModel):
        apple: str
        banana: str

    class Settings(BaseSettings):
        top: TopValue

    with pytest.raises(ValidationError):
        Settings()
    env.set('top', '{"banana": "secret_value"}')
    s = Settings(top={'apple': 'value'})
    assert s.top == {'apple': 'value', 'banana': 'secret_value'} 

def test_with_prefix(env):
    class Settings(BaseSettings):
        apple: str

        class Config:
            env_prefix = 'foobar_'

    with pytest.raises(ValidationError):
        Settings()
    env.set('foobar_apple', 'has_prefix')
    s = Settings()
    assert s.apple == 'has_prefix'