Если клиент запросит `http://example.com/items/foo` (`item_id` `"foo"`), то он получит статус-код 200 и ответ в формате JSON:

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

Но если клиент запросит `http://example.com/items/bar` (несуществующий `item_id` `"bar"`), то он получит статус-код 404 (ошибка "не найдено") и JSON-ответ в виде:

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

/// tip | "Подсказка"

```

### 📉 📨

🚥 👩‍💻 📨 `http://example.com/items/foo` ( `item_id` `"foo"`), 👈 👩‍💻 🔜 📨 🇺🇸🔍 👔 📟 2️⃣0️⃣0️⃣, & 🎻 📨:

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

✋️ 🚥 👩‍💻 📨 `http://example.com/items/bar` (🚫-🚫 `item_id` `"bar"`), 👈 👩‍💻 🔜 📨 🇺🇸🔍 👔 📟 4️⃣0️⃣4️⃣ ("🚫 🔎" ❌), & 🎻 📨:

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

/// tip

                                </a>
                                <c:forEach var="item" varStatus="s" items="${pathItems}">
                                    / <span><a
                                        href="${contextPath}/admin/storage/list/${f:u(item.id)}/">${f:h(item.name)}</a></span>
                                </c:forEach>

///

That means: "the variable `items` is a `list`, and each of the items in this list is a `str`".

/// tip

If you use Python 3.9 or above, you don't have to import `List` from `typing`, you can use the same regular `list` type instead.

///

By doing that, your editor can provide support even while processing items from the list:

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

                            <li class="breadcrumb-item active"><la:link href="/admin/elevateword">
                                <la:message key="labels.elevate_word_link_list"/>
                            </la:link></li>
                            <c:if test="${crudMode == 1}">
                                <li class="breadcrumb-item active"><la:message

{!../../docs_src/query_params_str_validations/tutorial008.py!}
```

## 별칭 매개변수

매개변수가 `item-query`이길 원한다고 가정해 봅시다.

마치 다음과 같습니다:

```
http://127.0.0.1:8000/items/?item-query=foobaritems
```

그러나 `item-query`은 유효한 파이썬 변수 이름이 아닙니다.

가장 가까운 것은 `item_query`일 겁니다.

하지만 정확히`item-query`이길 원합니다...

이럴 경우 `alias`를 선언할 수 있으며, 해당 별칭은 매개변수 값을 찾는 데 사용됩니다:

```Python hl_lines="9"

```Python hl_lines="13"
{!../../docs_src/query_params_str_validations/tutorial008.py!}
```

## 别名参数

假设你想要查询参数为 `item-query`。

像下面这样：

```
http://127.0.0.1:8000/items/?item-query=foobaritems
```

但是 `item-query` 不是一个有效的 Python 变量名称。

最接近的有效名称是 `item_query`。

但是你仍然要求它在 URL 中必须是 `item-query`...

这时你可以用 `alias` 参数声明一个别名，该别名将用于在 URL 中查找查询参数值：

```Python hl_lines="9"

        return encoded_dict
    if isinstance(obj, (list, set, frozenset, GeneratorType, tuple, deque)):
        encoded_list = []
        for item in obj:
            encoded_list.append(
                jsonable_encoder(
                    item,
                    include=include,
                    exclude=exclude,
                    by_alias=by_alias,
                    exclude_unset=exclude_unset,

	VersionID string `xml:"VersionId"`
}

// Metadata metadata items implemented to ensure XML marshaling works.
type Metadata struct {
	Items []struct {
		Key   string
		Value string
	}
}

// Set add items, duplicate items get replaced.
func (s *Metadata) Set(k, v string) {
	for i, item := range s.Items {
		if item.Key == k {
			s.Items[i] = struct {
				Key   string
				Value string
			}{

///

Dat betekent: “de variabele `items` is een `list`, en elk van de items in deze list is een `str`”.

/// tip

Als je Python 3.9 of hoger gebruikt, hoef je `List` niet te importeren uit `typing`, je kunt in plaats daarvan hetzelfde reguliere `list` type gebruiken.

///

Door dat te doen, kan je editor ondersteuning bieden, zelfs tijdens het verwerken van items uit de list: