How to use the dynaconf.Validator function in dynaconf

def test_dotted_validators(settings):

    settings.set(
        "PARAMS",
        {"PASSWORD": "secret", "SSL": {"CONTEXT": "SECURE", "ENABLED": True}},
    )

    settings.validators.register(
        Validator("PARAMS", must_exist=True, is_type_of=dict),
        Validator("PARAMS.PASSWORD", must_exist=True, is_type_of=str),
        Validator("PARAMS.SSL", must_exist=True, is_type_of=dict),
        Validator("PARAMS.SSL.ENABLED", must_exist=True, is_type_of=bool),
        Validator("PARAMS.NONEXISTENT", must_exist=False, is_type_of=str),
    )

    assert settings.validators.validate() is None

Validator("ZERO", is_type_of=int, eq=0),
        Validator("FALSE", is_type_of=bool, eq=False),
    )

    assert settings.validators.validate() is None

    settings.validators.register(
        Validator("TESTVALUEZZ", env="development"),
        Validator("TESTVALUE", eq="hello_world"),
    )

    with pytest.raises(ValidationError):
        settings.validators.validate()

    with pytest.raises(TypeError):
        Validator("A", condition=1)

    with pytest.raises(TypeError):
        Validator("A", when=1)

def test_validators(tmpdir):

    tmpfile = tmpdir.join("settings.toml")
    tmpfile.write(TOML)

    settings = LazySettings(
        ENV_FOR_DYNACONF="EXAMPLE",
        SETTINGS_FILE_FOR_DYNACONF=str(tmpfile),
        silent=True,
    )

    settings.validators.register(
        Validator("VERSION", "AGE", "NAME", must_exist=True),
        Validator("AGE", lte=30, gte=10),
        Validator("PROJECT", eq="hello_world"),
        Validator("PRESIDENT", env="DEVELOPMENT", ne="Trump"),
        Validator("SALARY", lt=1000000, gt=1000),
        Validator("DEV_SERVERS", must_exist=True, is_type_of=(list, tuple)),
        Validator("MYSQL_HOST", env="DEVELOPMENT", is_in=settings.DEV_SERVERS),
        Validator(
            "MYSQL_HOST", env="PRODUCTION", is_not_in=settings.DEV_SERVERS
        ),
        Validator("NAME", condition=lambda x: x in ("BRUNO", "MIKE")),
        Validator(
            "IMAGE_1",
            "IMAGE_2",
            env="development",
            must_exist=True,
            when=Validator(
                "BASE_IMAGE", must_exist=True, env=settings.ENV_FOR_DYNACONF

def test_equality():
    validator1 = Validator("VERSION", "AGE", "NAME", must_exist=True)
    validator2 = Validator("VERSION", "AGE", "NAME", must_exist=True)

    assert validator1 == validator2
    assert validator1 is not validator2

    validator3 = (
        Validator("IMAGE_1", when=Validator("BASE_IMAGE", must_exist=True)),
    )
    validator4 = (
        Validator("IMAGE_1", when=Validator("MYSQL_HOST", must_exist=True)),
    )

    assert validator3 != validator4

env="development",
            must_exist=True,
            when=Validator(
                "BASE_IMAGE", must_exist=True, env=settings.ENV_FOR_DYNACONF
            ),
        ),
        Validator(
            "IMAGE_4",
            "IMAGE_5",
            env=("development", "production"),
            must_exist=True,
            when=Validator(
                "BASE_IMAGE", must_exist=False, env=settings.ENV_FOR_DYNACONF
            ),
        ),
        Validator(
            "PORT",
            must_exist=True,
            ne=8000,
            when=Validator("MYSQL_HOST", eq="localhost"),
        ),
        #
        Validator("ZERO", is_type_of=int, eq=0),
        Validator("FALSE", is_type_of=bool, eq=False),
    )

    assert settings.validators.validate() is None

    settings.validators.register(
        Validator("TESTVALUEZZ", env="development"),
        Validator("TESTVALUE", eq="hello_world"),
    )

SETTINGS_FILE_FOR_DYNACONF=str(tmpfile),
        silent=True,
    )

    settings.validators.register(
        Validator("VERSION", "AGE", "NAME", must_exist=True),
        Validator("AGE", lte=30, gte=10),
        Validator("PROJECT", eq="hello_world"),
        Validator("PRESIDENT", env="DEVELOPMENT", ne="Trump"),
        Validator("SALARY", lt=1000000, gt=1000),
        Validator("DEV_SERVERS", must_exist=True, is_type_of=(list, tuple)),
        Validator("MYSQL_HOST", env="DEVELOPMENT", is_in=settings.DEV_SERVERS),
        Validator(
            "MYSQL_HOST", env="PRODUCTION", is_not_in=settings.DEV_SERVERS
        ),
        Validator("NAME", condition=lambda x: x in ("BRUNO", "MIKE")),
        Validator(
            "IMAGE_1",
            "IMAGE_2",
            env="development",
            must_exist=True,
            when=Validator(
                "BASE_IMAGE", must_exist=True, env=settings.ENV_FOR_DYNACONF
            ),
        ),
        Validator(
            "IMAGE_4",
            "IMAGE_5",
            env=("development", "production"),
            must_exist=True,
            when=Validator(
                "BASE_IMAGE", must_exist=False, env=settings.ENV_FOR_DYNACONF

        Validator("TESTVALUEZZ", must_exist=True),
    ],
)
def test_validation_error(validator_instance, tmpdir):
    tmpfile = tmpdir.join("settings.toml")
    tmpfile.write(TOML)

    settings = LazySettings(
        ENV_FOR_DYNACONF="EXAMPLE",
        SETTINGS_FILE_FOR_DYNACONF=str(tmpfile),
        silent=True,
    )
    settings.validators.register(validator_instance)
    with pytest.raises(ValidationError):
        settings.validators.validate()

"IMAGE_4",
            "IMAGE_5",
            env=("development", "production"),
            must_exist=True,
            when=Validator(
                "BASE_IMAGE", must_exist=False, env=settings.ENV_FOR_DYNACONF
            ),
        ),
        Validator(
            "PORT",
            must_exist=True,
            ne=8000,
            when=Validator("MYSQL_HOST", eq="localhost"),
        ),
        #
        Validator("ZERO", is_type_of=int, eq=0),
        Validator("FALSE", is_type_of=bool, eq=False),
    )

    assert settings.validators.validate() is None

    settings.validators.register(
        Validator("TESTVALUEZZ", env="development"),
        Validator("TESTVALUE", eq="hello_world"),
    )

    with pytest.raises(ValidationError):
        settings.validators.validate()

    with pytest.raises(TypeError):
        Validator("A", condition=1)

from dynaconf import LazySettings
from dynaconf import Validator

settings = LazySettings(ENV_FOR_DYNACONF="EXAMPLE")

settings.validators.register(
    Validator("VERSION", "AGE", "NAME", must_exist=True),
    Validator("AGE", lte=30, gte=10),
    Validator("PROJECT", eq="hello_world"),
    Validator("PRESIDENT", env="DEVELOPMENT", ne="Trump"),
    Validator("SALARY", lt=1000000, gt=1000),
    Validator("DEV_SERVERS", must_exist=True, is_type_of=(list, tuple)),
    Validator("MYSQL_HOST", env="DEVELOPMENT", is_in=settings.DEV_SERVERS),
    Validator("MYSQL_HOST", env="PRODUCTION", is_not_in=settings.DEV_SERVERS),
    Validator("NAME", condition=lambda x: x in ("BRUNO", "MIKE")),
    Validator(
        "IMAGE_1",
        "IMAGE_2",
        env="development",
        must_exist=True,
        when=Validator(
            "BASE_IMAGE", must_exist=True, env=settings.ENV_FOR_DYNACONF
        ),
    ),
    Validator(

from dynaconf import LazySettings
from dynaconf import Validator

settings = LazySettings(ENV_FOR_DYNACONF="EXAMPLE")

settings.validators.register(
    Validator("VERSION", "AGE", "NAME", must_exist=True),
    Validator("AGE", lte=30, gte=10),
    Validator("PROJECT", eq="hello_world"),
    Validator("PRESIDENT", env="DEVELOPMENT", ne="Trump"),
    Validator("SALARY", lt=1000000, gt=1000),
    Validator("DEV_SERVERS", must_exist=True, is_type_of=(list, tuple)),
    Validator("MYSQL_HOST", env="DEVELOPMENT", is_in=settings.DEV_SERVERS),
    Validator("MYSQL_HOST", env="PRODUCTION", is_not_in=settings.DEV_SERVERS),
    Validator("NAME", condition=lambda x: x in ("BRUNO", "MIKE")),
    Validator(
        "IMAGE_1",
        "IMAGE_2",
        env="development",
        must_exist=True,
        when=Validator(
            "BASE_IMAGE", must_exist=True, env=settings.ENV_FOR_DYNACONF
        ),
    ),
    Validator(
        "IMAGE_4",
        "IMAGE_5",
        env=("development", "production"),