oauth2_scheme = OAuth2AuthorizationCodeBearer(
    authorizationUrl="authorize",
    tokenUrl="token",
    description="OAuth2 Code Bearer",
    auto_error=True,
)


@app.get("/items/")
async def read_items(token: Optional[str] = Security(oauth2_scheme)):
    return {"token": token}


client = TestClient(app)


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

from fastapi.security import OAuth2PasswordBearer
from fastapi.testclient import TestClient

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():

from inline_snapshot import snapshot

from .utils import needs_py310


def get_client():
    app = FastAPI()
    with pytest.warns(FastAPIDeprecationWarning):

        @app.post("/items/")
        async def read_items(
            q: Annotated[str | None, Form(regex="^fixedquery$")] = None,
        ):
            if q:
                return f"Hello {q}"
            else:
                return "Hello World"

from fastapi.testclient import TestClient

from .utils import needs_py310


def get_client():
    app = FastAPI()
    with pytest.warns(FastAPIDeprecationWarning):

        @app.get("/items/")
        async def read_items(
            q: Annotated[str | None, Query(regex="^fixedquery$")] = None,
        ):
            if q:
                return f"Hello {q}"
            else:
                return "Hello World"

* Присваивании этого результата параметру в вашей *функции обработки пути*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

Таким образом, вы пишете общий код один раз, а **FastAPI** позаботится о его вызове для ваших *операций пути*.

/// check | Проверка

)
async def read_with_get_token():
    return {"message": "Admin Access"}


router = APIRouter(dependencies=[Security(oauth2_scheme, scopes=["read"])])


@router.get("/items/")
async def read_items(token: Optional[str] = Depends(oauth2_scheme)):
    return {"token": token}


@router.post("/items/")
async def create_item(
    token: Optional[str] = Security(oauth2_scheme, scopes=["read", "write"]),
):

///

接收到新的请求时，**FastAPI** 执行如下操作：

* 用正确的参数调用依赖项函数（「可依赖项」）
* 获取函数返回的结果
* 把函数返回的结果赋值给*路径操作函数*的参数

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

这样，只编写一次代码，**FastAPI** 就可以为多个*路径操作*共享这段代码 。

/// check | 检查

注意，无需创建专门的类，并将之传递给 **FastAPI** 以进行「注册」或执行类似的操作。

* Get the result from your function.
* Assign that result to the parameter in your *path operation function*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

This way you write shared code once and **FastAPI** takes care of calling it for your *path operations*.

/// check

* Obtener el resultado de tu función.
* Asignar ese resultado al parámetro en tu *path operation function*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

De esta manera escribes código compartido una vez y **FastAPI** se encarga de llamarlo para tus *path operations*.

/// check | Revisa

* Obter o resultado da função.
* Atribuir esse resultado para o parâmetro em sua *função de operação de rota*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

Assim, você escreve um código compartilhado apenas uma vez e o **FastAPI** se encarrega de chamá-lo em suas *operações de rota*.