Par exemple, le modèle ci-dessus déclare un "objet" JSON (ou `dict` Python) tel que :

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

...`description` et `tax` étant des attributs optionnels (avec `None` comme valeur par défaut), cet "objet" JSON serait aussi valide :

    )
    assert response.status_code == 200, response.text
    assert response.json() == {
        "item_id": 5,
        "item": {
            "name": "Foo",
            "description": None,
            "price": 35.4,
            "tax": None,
            "tags": [],
        },
    }


def test_put_empty_body(client: TestClient):
    response = client.put(
        "/items/5",
        json={},
    )

终于，我们英雄（hero）的身份得到了保护！ 🥷

它还重新声明了 `id: int` 。这样我们便与 API 客户端建立了一种**约定**，使他们始终可以期待 `id` 存在并且是一个整数 `int`（永远不会是 `None` ）。

/// tip

确保返回模型始终提供一个值并且始终是 `int` （而不是 `None` ）对 API 客户端非常有用，他们可以在这种确定性下编写更简单的代码。

此外，**自动生成的客户端**将拥有更简洁的接口，这样与您的 API 交互的开发者就能更轻松地使用您的 API。😎

///

`HeroPublic` 中的所有字段都与 `HeroBase` 中的相同，其中 `id` 声明为 `int` （不是 `None` ）：

* `id`
* `name`
* `age`
* `secret_name`

import subprocess

from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()
    page.goto("http://localhost:8000/docs")

version: "2"
linters:
  default: none
  enable:
    - durationcheck
    - forcetypeassert
    - gocritic
    - gomodguard
    - govet
    - ineffassign
    - misspell
    - revive
    - staticcheck
    - unconvert
    - unused
    - usetesting
    - whitespace
  settings:
    misspell:
      locale: US
    staticcheck:
      checks:
        - all
        - -SA1008
        - -SA1019
        - -SA4000

/**
 * Internal use only
 *
 * @author mbechler
 *
 * <p>This interface is intended for internal use.</p>
 */
public enum RequestParam {

    /**
     * No special request parameters.
     */
    NONE,

    /**
     * Wait indefinitely for a response
     */
    NO_TIMEOUT,

    /**
     * Do not retry request on failure
     */
    NO_RETRY,

    /**

app = FastAPI()

security = HTTPBearer(auto_error=False)


@app.get("/users/me")
def read_current_user(
    credentials: Optional[HTTPAuthorizationCredentials] = Security(security),
):
    if credentials is None:
        return {"msg": "Create an account first"}
    return {"scheme": credentials.scheme, "credentials": credentials.credentials}


client = TestClient(app)


def test_security_http_bearer():

app = FastAPI()

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/token", auto_error=False)


@app.get("/items/")
async def read_items(token: Optional[str] = Security(oauth2_scheme)):
    if token is None:
        return {"msg": "Create an account first"}
    return {"token": token}


client = TestClient(app)


def test_no_token():
    response = client.get("/items")

from fastapi import APIRouter, FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel, HttpUrl

app = FastAPI()


class Invoice(BaseModel):
    id: str
    title: Optional[str] = None
    customer: str
    total: float


class InvoiceEvent(BaseModel):
    description: str
    paid: bool


class InvoiceEventReceived(BaseModel):
    ok: bool

import subprocess

from playwright.sync_api import Playwright, sync_playwright


# Run playwright codegen to generate the code below, copy paste the sections in run()
def run(playwright: Playwright) -> None:
    browser = playwright.chromium.launch(headless=False)
    # Update the viewport manually
    context = browser.new_context(viewport={"width": 960, "height": 1080})
    page = context.new_page()
    page.goto("http://localhost:8000/docs")