這就是一個 Python 函式。

它將會在 **FastAPI** 收到一個請求時被呼叫，使用 `GET` 操作。

在這種情況下，它是一個 `async` 函式。

---

你可以將它定義為一個正常的函式，而不是 `async def`:

{* ../../docs_src/first_steps/tutorial003.py h1[7] *}

/// note

如果你不知道差別，請查看 [Async: *"In a hurry?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

### 第五步：回傳內容

이것은 파이썬 함수입니다.

URL "`/`"에 대한 `GET` 작동을 사용하는 요청을 받을 때마다 **FastAPI**에 의해 호출됩니다.

위의 예시에서 이 함수는 `async`(비동기) 함수입니다.

---

`async def`을 이용하는 대신 일반 함수로 정의할 수 있습니다:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note | 참고

차이점을 모르겠다면 [Async: *"바쁘신 경우"*](../async.md#_1){.internal-link target=_blank}을 확인하세요.

///

### 5 단계: 콘텐츠 반환

from fastapi import FastAPI
from fastapi.responses import ORJSONResponse

app = FastAPI(default_response_class=ORJSONResponse)


@app.get("/items/")
async def read_items():

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/", openapi_extra={"x-aperture-labs-portal": "blue"})
async def read_items():

                            "description": {"type": "string"},
                        },
                    }
                }
            },
            "required": True,
        },
    },
)
async def create_item(request: Request):
    raw_body = await request.body()
    data = magic_data_reader(raw_body)

    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None
    tags: set[str] = set()
    images: Union[list[Image], None] = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):
    results = {"item_id": item_id, "item": item}

    images: list[Image] | None = None


class Offer(BaseModel):
    name: str
    description: str | None = None
    price: float
    items: list[Item]


@app.post("/offers/")
async def create_offer(offer: Offer):

from datetime import datetime, time, timedelta
from typing import Union
from uuid import UUID

from fastapi import Body, FastAPI

app = FastAPI()


@app.put("/items/{item_id}")
async def read_items(
    item_id: UUID,
    start_datetime: datetime = Body(),
    end_datetime: datetime = Body(),
    process_after: timedelta = Body(),
    repeat_at: Union[time, None] = Body(default=None),
):

from fastapi import FastAPI

app = FastAPI(swagger_ui_parameters={"syntaxHighlight": False})


@app.get("/users/{username}")
async def read_user(username: str):

from fastapi import FastAPI, Header

app = FastAPI()


@app.get("/items/")
async def read_items(
    strange_header: str | None = Header(default=None, convert_underscores=False),
):