validate yaml file with dynaconf or schema in python

Question

I have a fairly yaml file corresponding to nested dict, which I want to validate with dynaconf. I'm following the guide here: https://www.dynaconf.com/validation/ but their example is pretty simple, and I can't find a way to validate data which corresponds to nested dictionaries, like in my example below:

---
item1:
    - prod1: val1
    - prod2
        - proda: vala
        - prodb: |
            valb1
            valb2
version: 1
---
item2:
    prodx: valx

For instance I would like to make sure that vala, valb2, valx all should exist.

settings = Dynaconf(
    settings_files=['file.yml'],
    validators=[
        Validator("proda", must_exist=True, eq='vala'),
        Validator("version", must_exist=True, is_type_of=int),
        ...
    ]

Or, if you know something else, like "schema" library, which could be more suitable for this job let me know. p.s. I also want to keep multiple yaml configs in one file, separated by ---

Answer 1

As a rule of thumb, when it comes to open source tools, go through both the docs and the tests suit.

Ex from one of their many tests:

YAML = """
server:
    hostname: "localhost"
    port: 22
    users:
      - "Bruno"
      - "Lula"
app:
    name: "testname"
    path: "/tmp/app_startup"
    args:
        arg1: "a"
        arg2: "b"
        arg3: "c"
hasemptyvalues:
    key1:
    key2:
    key3: null
    key4: "@empty"
"""

@pytest.fixture
def yaml_validators_good():
    return [
        Validator(
            "server.hostname", "server.port", "server.users", must_exist=True
        ),
        Validator(
            "app.name",
            "app.path",
            "app.args.arg1",
            "app.args.arg2",
            "app.args.arg3",
            must_exist=True,
        ),
    ]


@pytest.fixture
def yaml_validators_bad():
    return [
        Validator("missing.value", must_exist=True),
        Validator("app.missing", must_exist=True),
        Validator("app.args.missing", must_exist=True),
    ]