*
 * <p>This class should not be assumed to be universally superior to {@code
 * java.util.LinkedHashSet}. Generally speaking, this class reduces object allocation and memory
 * consumption at the price of moderately increased constant factors of CPU. Only use this class
 * when there is a specific reason to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 */
@GwtIncompatible // not worth using in GWT for now

*  <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">🗒</a>:

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

👆 🔜 🤚 🛠️ 📟 👆 5️⃣📆 🤔 💪 ⏭. 🖼, `price` 🔑 🔘 🎻 💪 (👈 💪 ✔️ 🐦) 👈 👟 ⚪️➡️ 📨.

🙅‍♂ 🌖 ⌨ ❌ 🔑 📛, 👟 🔙 &amp; ➡ 🖖 🩺, ⚖️ 📜 🆙 &amp; 🔽 🔎 🚥 👆 😒 ⚙️ `username` ⚖️ `user_name`.

### 📏

![editor ondersteuning](https://fastapi.tiangolo.com/img/pycharm-completion.png)

Je krijgt autocomletion die je voorheen misschien zelfs voor onmogelijk had gehouden. Zoals bijvoorbeeld de `price` key in een JSON body (die genest had kunnen zijn) die afkomstig is van een request.

{* ../../docs_src/body_updates/tutorial001.py hl[30,31,32,33,34,35] *}

既存のデータを置き換えるべきデータを受け取るために`PUT`は使用されます。

### 置換についての注意

つまり、`PUT`を使用して以下のボディで項目`bar`を更新したい場合は:

```Python
{
    "name": "Barz",
    "price": 3,
    "description": None,
}
```

すでに格納されている属性`"tax": 20.2`を含まないため、入力モデルのデフォルト値は`"tax": 10.5`です。

そして、データはその「新しい」`10.5`の`tax`と共に保存されます。

## `PATCH`による部分的な更新

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

Вы будете получать автодополнение кода даже там, где вы считали это невозможным раньше.
Как пример, ключ `price` внутри тела JSON (который может быть вложенным), приходящего в запросе.

 *
 * <p>This class should not be assumed to be universally superior to {@code java.util.HashSet}.
 * Generally speaking, this class reduces object allocation and memory consumption at the price of
 * moderately increased constant factors of CPU. Only use this class when there is a specific reason
 * to prioritize memory over CPU.
 *
 * @author Dimitris Andreou
 * @author Jon Noack
 */

   */
  public List<Long> asList() {
    /*
     * Typically we cache this kind of thing, but much repeated use of this view is a performance
     * anti-pattern anyway. If we cache, then everyone pays a price in memory footprint even if
     * they never use this method.
     */
    return new AsList(this);
  }

  private static final class AsList extends AbstractList<Long>

   */
  public List<Integer> asList() {
    /*
     * Typically we cache this kind of thing, but much repeated use of this view is a performance
     * anti-pattern anyway. If we cache, then everyone pays a price in memory footprint even if
     * they never use this method.
     */
    return new AsList(this);
  }

  private static final class AsList extends AbstractList<Integer>

두 번째 매개변수는  `dict`의 값(value)입니다.

{* ../../docs_src/python_types/tutorial008.py hl[1,4] *}


이 뜻은 아래와 같습니다:

* 변수 `prices`는 `dict`이다:
    * `dict`의 키(key)는 `str`타입이다. (각 아이템의 이름(name))
    * `dict`의 값(value)는 `float`타입이다. (각 아이템의 가격(price))

#### `Optional`

`str`과 같이 타입을 선언할 때 `Optional`을 쓸 수도 있는데, "선택적(Optional)"이기때문에 `None`도 될 수 있습니다:

```Python hl_lines="1  4"

![soporte del editor](https://fastapi.tiangolo.com/img/pycharm-completion.png)

Obtendrás autocompletado en código que podrías considerar imposible antes. Por ejemplo, la clave `price` dentro de un cuerpo JSON (que podría haber estado anidado) que proviene de un request.