from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None

    class Config:
        schema_extra = {
            "examples": [
                {
                    "name": "Foo",
                    "description": "A very nice Item",
                    "price": 35.4,
                    "tax": 3.2,

                    for (int i = 0; i < 100; i++) {
                      set.add("extra" + i);
                    }
                    for (int i = 0; i < 100; i++) {
                      set.remove("extra" + i);
                    }
                    set.trimToSize();
                    return set;
                  }
                })

Vous pouvez étendre le schéma OpenAPI pour une *opération de chemin* en utilisant le paramètre `openapi_extra`.

### Extensions OpenAPI

Cet `openapi_extra` peut être utile, par exemple, pour déclarer [OpenAPI Extensions](https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#specificationExtensions) :

```Python hl_lines="6"

from pydantic import BaseModel, ValidationError

app = FastAPI()


class Item(BaseModel):
    name: str
    tags: List[str]


@app.post(
    "/items/",
    openapi_extra={
        "requestBody": {
            "content": {"application/x-yaml": {"schema": Item.model_json_schema()}},
            "required": True,
        },
    },
)
async def create_item(request: Request):

from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/", openapi_extra={"x-custom-extension": "value"})
def route_with_extras():
    return {}


client = TestClient(app)


def test_get_route():
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert response.json() == {}


def test_openapi():

 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtCompatible;

/**
 * Holder for extra methods of {@code Objects} only in web. Intended to be empty for regular
 * version.
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault

 * limitations under the License.
 */
package okhttp3.testing

@Target(AnnotationTarget.CLASS, AnnotationTarget.FUNCTION)
@Retention(AnnotationRetention.RUNTIME)
/**
 * Annotation marking a test as flaky, and requires extra logging and linking against
 * a known github issue.  This does not ignore the failure.
 */

## Adicione informações extras

Você pode declarar informação extra em `Field`, `Query`, `Body`, etc. E isso será incluído no JSON Schema gerado.

Você irá aprender mais sobre adicionar informações extras posteriormente nessa documentação, quando estiver aprendendo a declarar exemplos.

## Recapitulando

Você pode usar `Field` do Pydantic para declarar validações extras e metadados para atributos do modelo.

* <a href="https://docs.pydantic.dev/latest/usage/types/extra_types/extra_types/" target="_blank"><code>pydantic-extra-types</code></a> - for extra types to be used with Pydantic.

Used by Starlette:

* <a href="https://www.python-httpx.org" target="_blank"><code>httpx</code></a> - Required if you want to use the `TestClient`.

Sie werden später mehr darüber lernen, wie man zusätzliche Information unterbringt, wenn Sie lernen, Beispiele zu deklarieren.

!!! warning "Achtung"