tags: set[str] = set()


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    description="Create an item with all the information, name, description, price, tax and a set of unique tags",
)
async def create_item(item: Item):

    tags: set[str] = set()


@app.post(
    "/items/",
    response_model=Item,
    summary="Create an item",
    description="Create an item with all the information, name, description, price, tax and a set of unique tags",
)
async def create_item(item: Item):

    - **name**: each item must have a name
    - **description**: a long description
    - **price**: required
    - **tax**: if the item doesn't have tax, you can omit this
    - **tags**: a set of unique tag strings for this item
    """

    - **name**: each item must have a name
    - **description**: a long description
    - **price**: required
    - **tax**: if the item doesn't have tax, you can omit this
    - **tags**: a set of unique tag strings for this item
    """

    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

## Set types

But then we think about it, and realize that tags shouldn't repeat, they would probably be unique strings.

And Python has a special data type for sets of unique items, the `set`.

Then we can declare `tags` as a set of strings:

=== "Python 3.10+"

    ```Python hl_lines="12"

                    "operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/json": {

마찬가지로 예제에서 `tags`를 구체적으로 "문자열의 리스트"로 만들 수 있습니다:

```Python hl_lines="14"
{!../../../docs_src/body_nested_models/tutorial002.py!}
```

## 집합 타입

그런데 생각해보니 태그는 반복되면 안 돼고, 고유한(Unique) 문자열이어야 할 것 같습니다.

그리고 파이썬은 집합을 위한 특별한 데이터 타입 `set`이 있습니다.

그렇다면 `Set`을 임포트 하고 `tags`를 `str`의 `set`으로 선언할 수 있습니다:

```Python hl_lines="1  14"
{!../../../docs_src/body_nested_models/tutorial003.py!}
```

Hier verwendet sie beispielsweise den ersten Tag (Sie werden wahrscheinlich nur einen Tag haben) und den Namen der *Pfadoperation* (den Funktionsnamen).

Anschließend können Sie diese benutzerdefinierte Funktion als Parameter `generate_unique_id_function` an **FastAPI** übergeben:

=== "Python 3.9+"

    ```Python hl_lines="6-7  10"
    {!> ../../../docs_src/generate_clients/tutorial003_py39.py!}
    ```

=== "Python 3.8+"

👆 💪 🛃 👈 🔢. ⚫️ ✊ `APIRoute` & 🔢 🎻.

🖼, 📥 ⚫️ ⚙️ 🥇 🔖 (👆 🔜 🎲 ✔️ 🕴 1️⃣ 🔖) & *➡ 🛠️* 📛 (🔢 📛).

👆 💪 ⤴️ 🚶‍♀️ 👈 🛃 🔢 **FastAPI** `generate_unique_id_function` 🔢:

=== "🐍 3️⃣.6️⃣ & 🔛"

    ```Python hl_lines="8-9  12"
    {!> ../../../docs_src/generate_clients/tutorial003.py!}
    ```

=== "🐍 3️⃣.9️⃣ & 🔛"

                """
            ),
        ] = None,
        generate_unique_id_function: Annotated[
            Callable[[routing.APIRoute], str],
            Doc(
                """
                Customize the function used to generate unique IDs for the *path
                operations* shown in the generated OpenAPI.