```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


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


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

```Python hl_lines="4  9-12  25-27"
from typing import Optional

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


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


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

 *
 * <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

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

شما پیشنهاد های تکمیل خودکاری را خواهید گرفت که حتی ممکن است قبلا آن را غیرممکن تصور میکردید. به عنوان مثال کلید `price` در داخل بدنه JSON (که میتوانست تودرتو نیز باشد) که از یک درخواست آمده است.

دیگر خبری از تایپ کلید اشتباهی، برگشتن به مستندات یا پایین بالا رفتن برای فهمیدن اینکه شما از `username` یا `user_name` استفاده کرده اید نیست.

### مختصر

*  `prices` değişkeni `dict` tipindedir:
    *  `dict` değişkeninin `key` değeri  `str` tipindedir (herbir item'ın "name" değeri).
    *  `dict` değişkeninin `value` değeri `float` tipindedir (lherbir item'ın "price" değeri).

#### `Optional`

`Optional` bir değişkenin `str`gibi bir tipi olabileceğini ama isteğe bağlı olarak tipinin `None` olabileceğini belirtir:

```Python hl_lines="1  4"

 *
 * <p>This class should not be assumed to be universally superior to {@code
 * java.util.LinkedHashMap}. 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
 */

{!../../docs_src/body_updates/tutorial001.py!}
```

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

*  <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 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.

![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.