from .utils import needs_pydanticv1, needs_pydanticv2


@needs_pydanticv2
def test_model_field_default_required():
    # For coverage
    field_info = FieldInfo(annotation=str)
    field = ModelField(name="foo", field_info=field_info)
    assert field.default is Undefined


@needs_pydanticv1
def test_upload_file_dummy_with_info_plain_validator_function():
    # For coverage

    ```

Das würde bedeuten, dass **FastAPI** einen Body erwartet wie:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

Wiederum, nur mit dieser Deklaration erhalten Sie von **FastAPI**:

def main(user_id: str):
    return user_id


# A Pydantic model
class User(BaseModel):
    id: int
    name: str
    joined: date
```

Sau đó có thể được sử dụng:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {
    "id": 4,
    "name": "Mary",
    "joined": "2018-11-30",
}

my_second_user: User = User(**second_user_data)
```

!!! info

但是，如果你的数据在具有默认值的模型字段中有实际的值，例如 ID 为 `bar` 的项：

```Python hl_lines="3  5"
{
    "name": "Bar",
    "description": "The bartenders",
    "price": 62,
    "tax": 20.2
}
```

这些值将包含在响应中。

#### 具有与默认值相同值的数据

如果数据具有与默认值相同的值，例如 ID 为 `baz` 的项：

```Python hl_lines="3  5-6"
{
    "name": "Baz",
    "description": None,
    "price": 50.2,
    "tax": 10.5,
    "tags": []
}

                    "parameters": [
                        {
                            "required": True,
                            "schema": {"title": "Item Id", "type": "string"},
                            "name": "item_id",
                            "in": "path",
                        },
                        {
                            "required": False,
                            "schema": IsDict(

import pytest
from dirty_equals import IsOneOf
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(name="client")
def get_client():
    from docs_src.extra_models.tutorial003_py310 import app

    client = TestClient(app)
    return client


@needs_py310
def test_get_car(client: TestClient):
    response = client.get("/items/item1")
    assert response.status_code == 200, response.text

---

To dopiero początek, ale już masz mniej-więcej pojęcie jak to wszystko działa.

Spróbuj zmienić linijkę:

```Python
    return {"item_name": item.name, "item_id": item_id}
```

...z:

```Python
        ... "item_name": item.name ...
```

...na:

```Python
        ... "item_price": item.price ...
```

---

Мы только немного копнули поверхность, но вы уже поняли, как все это работает.

Попробуйте изменить строку с помощью:

```Python
    return {"item_name": item.name, "item_id": item_id}
```

...из:

```Python
        ... "item_name": item.name ...
```

...в:

```Python
        ... "item_price": item.price ...
```

Questa è solo la punta dell'iceberg, ma dovresti avere già un'idea di come il tutto funzioni.

Prova a cambiare questa riga di codice:

```Python
    return {"item_name": item.name, "item_id": item_id}
```

...da:

```Python
        ... "item_name": item.name ...
```

...a:

```Python
        ... "item_price": item.price ...
```

  ]
}
```

because the path parameter `item_id` had a value of `"foo"`, which is not an `int`.

The same error would appear if you provided a `float` instead of an `int`, as in: <a href="http://127.0.0.1:8000/items/4.2" class="external-link" target="_blank">http://127.0.0.1:8000/items/4.2</a>

!!! check
    So, with the same Python type declaration, **FastAPI** gives you data validation.