///

Cela signifie : « la variable `items` est une `list`, et chacun des éléments de cette liste est un `str` ».

En faisant cela, votre éditeur peut vous fournir de l'aide même pendant le traitement des éléments de la liste :

<img src="/img/python-types/image05.png">

Sans types, c'est presque impossible à réaliser.

Remarquez que la variable `item` est l'un des éléments de la liste `items`.

from fastapi import FastAPI

app = FastAPI()


@app.get("/items/", tags=["items"])
async def read_items():
    return [{"name": "Foo", "price": 42}]


@app.get("/users/", tags=["users"])
async def read_users():
    return [{"username": "johndoe"}]


@app.get("/elements/", tags=["items"], deprecated=True)
async def read_elements():

      "input": null
    }
  ]
}
```

由於 `needy` 是必填參數，你需要在 URL 中設定它：

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...這樣就會成功：

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

當然，你可以同時定義部分參數為必填、部分有預設值、部分為選填：

{* ../../docs_src/query_params/tutorial006_py310.py hl[8] *}

在此例中，有 3 個查詢參數：

* `needy`，必填的 `str`。

```JSON
{
  "item": "The Foo Wrestlers"
}
```

But if the client requests `http://example.com/items/bar` (a non-existent `item_id` `"bar"`), that client will receive an HTTP status code of 404 (the "not found" error), and a JSON response of:

```JSON
{
  "detail": "Item not found"
}
```

/// tip

When raising an `HTTPException`, you can pass any value that can be converted to JSON as the parameter `detail`, not only `str`.

from fastapi import FastAPI
from fastapi.responses import UJSONResponse

app = FastAPI()


@app.get("/items/", response_class=UJSONResponse)
async def read_items():

### 回應結果 { #the-resulting-response }

如果用戶端請求 `http://example.com/items/foo`（`item_id` 為 `"foo"`），會收到 200 的 HTTP 狀態碼，以及以下 JSON 回應：

```JSON
{
  "item": "The Foo Wrestlers"
}
```

但如果用戶端請求 `http://example.com/items/bar`（不存在的 `item_id` `"bar"`），會收到 404（"not found"）的 HTTP 狀態碼，以及以下 JSON 回應：

```JSON
{
  "detail": "Item not found"
}
```

/// tip

app = FastAPI()


@app.get("/items/{item_id}")
async def read_item(
    item_id: Annotated[int, Path(ge=1, description="The item ID")],
    q: Annotated[str | None, Query(max_length=50)] = None,
):
    return {"message": "Hello World"}
```

instead of:

```python
# DO NOT DO THIS
@app.get("/items/{item_id}")
async def read_item(
    item_id: int = Path(ge=1, description="The item ID"),

        from pydantic import BaseModel

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

        app = FastAPI()
        router = APIRouter()

        @router.put("/items/{item_id}")
        def replace_item(item_id: str, item: Item):
            return {"message": "Item replaced", "id": item_id}

        app.include_router(router)
        ```

      "input": null
    }
  ]
}
```

`needy`는 필수 매개변수이므로 URL에 반드시 설정해줘야 합니다:

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...아래처럼 작동합니다:

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

그리고 물론, 일부 매개변수는 필수로, 다른 일부는 기본값을, 또 다른 일부는 선택적으로 선언할 수 있습니다:

{* ../../docs_src/query_params/tutorial006_py310.py hl[8] *}

Bu durumda, şuraya giderseniz:

```
http://127.0.0.1:8000/items/foo?short=1
```

veya

```
http://127.0.0.1:8000/items/foo?short=True
```

veya

```
http://127.0.0.1:8000/items/foo?short=true
```

veya

```
http://127.0.0.1:8000/items/foo?short=on
```

veya

```
http://127.0.0.1:8000/items/foo?short=yes
```