app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Ou utilisez <code>async def</code> ...</summary>

Si votre code utilise `async` / `await`, utilisez `async def` :

```Python hl_lines="9  14"

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>或可以使用 <code>async def</code>...</summary>

如果你的程式使用 `async` / `await`，請使用 `async def`：

```Python hl_lines="9  14"
from typing import Union

async def get_db():
    db = DBSession()
    try:
        yield db
    finally:

            )
        return self.openapi_schema

    def setup(self) -> None:
        if self.openapi_url:
            urls = (server_data.get("url") for server_data in self.servers)
            server_urls = {url for url in urls if url}

            async def openapi(req: Request) -> JSONResponse:
                root_path = req.scope.get("root_path", "").rstrip("/")

from typing import Optional


def say_hi(name: Optional[str]):

    tax: Union[float, None] = None
    tags: Set[str] = set()


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    response_description="The created item",
)
async def create_item(item: Item):
    """
    Create an item with all the information:

    - **name**: each item must have a name
    - **description**: a long description
    - **price**: required

    }

    public String getMimeType( String extension ) throws IOException {
        return getMimeType( extension, "application/octet-stream" );
    }
    public String getMimeType( String extension, String def ) throws IOException {
        int state, t, x, i, off;
        byte ch;
        byte[] type = new byte[128];
        byte[] buf = new byte[16];
        byte[] ext = extension.toLowerCase().getBytes( "ASCII" );

def get_full_name(first_name, last_name):
    full_name = first_name.title() + " " + last_name.title()
    return full_name

def process_items(prices: dict[str, float]):
    for item_name, item_price in prices.items():
        print(item_name)

from typing import Set, Tuple


def process_items(items_t: Tuple[int, int, str], items_s: Set[bytes]):