Defining non key-value models

non_key_value_model.py

from pydantic import BaseModel


class Age(BaseModel):
    __root__: int


def test_specialized_models_are_not_equal_to_their_primitives():
    age = Age(__root__=42)
    assert age != 42


def test_age_can_also_be_parsed():
    age = Age.parse_obj(42)
    assert age != 42


def test_specialized_models_can_ensure_we_use_the_correct_types():
    age = Age(__root__='43')
    assert age.__root__ == 43


def age_in_days(age: Age) -> int:
    return age.__root__ * 365


def test_age_in_days_only_needs_to_deal_with_ints():
    age = Age.parse_obj('42')
    assert age_in_days(age) == 42 * 365


# note that mypy raises an error when trying the following
# will raise a mypy error
# age_in_days(age='not an age')


class Person(BaseModel):
    age: Age
    name: str


def test_age_is_converted_to_primitive_when_being_jsoned():
    person = Person.parse_obj({'age': 37, 'name': 'John'})
    assert person.json() == '{"age": 37, "name": "John"}'