for (const method of Object.keys(pathData)) {
        const operation = pathData[method]
        if (operation.tags && operation.tags.length > 0) {
          const tag = operation.tags[0]
          const operationId = operation.operationId
          const toRemove = `${tag}-`
          if (operationId.startsWith(toRemove)) {
            const newOperationId = operationId.substring(toRemove.length)

<img src="/img/tutorial/generate-clients/image05.png">

## FastAPI App with Tags

In many cases your FastAPI app will be bigger, and you will probably use tags to separate different groups of *path operations*.

For example, you could have a section for **items** and another section for **users**, and they could be separated by tags:

=== "Python 3.9+"

    ```Python hl_lines="21  26  34"

    ```

## Set-Typen

Aber dann denken wir darüber nach und stellen fest, dass sich die Tags nicht wiederholen sollen, es sollen eindeutige Strings sein.

Python hat einen Datentyp speziell für Mengen eindeutiger Dinge: das <abbr title="Menge">`set`</abbr>.

Deklarieren wir also `tags` als Set von Strings.

=== "Python 3.10+"

    ```Python hl_lines="12"

⏮️ 👉 📳, 🏧 🛠️ 🩺 🔜 👀 💖:

<img src="/img/tutorial/metadata/image01.png">

## 🗃 🔖

👆 💪 🚮 🌖 🗃 🎏 🔖 ⚙️ 👪 👆 ➡ 🛠️ ⏮️ 🔢 `openapi_tags`.

⚫️ ✊ 📇 ⚗ 1️⃣ 📖 🔠 🔖.

🔠 📖 💪 🔌:

* `name` (**✔**): `str` ⏮️ 🎏 📛 👆 ⚙️ `tags` 🔢 👆 *➡ 🛠️* &amp; `APIRouter`Ⓜ.
* `description`: `str` ⏮️ 📏 📛 🔖. ⚫️ 💪 ✔️ ✍ &amp; 🔜 🎦 🩺 🎚.
* `externalDocs`: `dict` 🔬 🔢 🧾 ⏮️:

    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/users/": {
                "get": {
                    "tags": ["users"],
                    "summary": "Read Users",
                    "operationId": "read_users_users__get",
                    "parameters": [
                        {

    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/users/": {
                "get": {
                    "tags": ["users"],
                    "summary": "Read Users",
                    "operationId": "read_users_users__get",
                    "parameters": [
                        {

from typing import List

import yaml
from fastapi import FastAPI, HTTPException, Request
from pydantic import BaseModel, ValidationError

app = FastAPI()


class Item(BaseModel):
    name: str
    tags: List[str]


@app.post(
    "/items/",
    openapi_extra={
        "requestBody": {
            "content": {"application/x-yaml": {"schema": Item.model_json_schema()}},
            "required": True,
        },
    },

{!../../../docs_src/metadata/tutorial001_1.py!}
```

## Metadata for tags

You can also add additional metadata for the different tags used to group your path operations with the parameter `openapi_tags`.

It takes a list containing one dictionary for each tag.

Each dictionary can contain:

* `name` (**required**): a `str` with the same tag name you use in the `tags` parameter in your *path operations* and `APIRouter`s.

#### 具有与默认值相同值的数据

如果数据具有与默认值相同的值，例如 ID 为 `baz` 的项：

```Python hl_lines="3  5-6"
{
    "name": "Baz",
    "description": None,
    "price": 50.2,
    "tax": 10.5,
    "tags": []
}
```

即使 `description`、`tax` 和 `tags` 具有与默认值相同的值，FastAPI 足够聪明 (实际上是 Pydantic 足够聪明) 去认识到这一点，它们的值被显式地所设定（而不是取自默认值）。

因此，它们将包含在 JSON 响应中。

!!! tip
    请注意默认值可以是任何值，而不仅是`None`。

ID`baz`のitemのようにデフォルト値と同じ値を持つデータの場合:

```Python hl_lines="3 5 6"
{
    "name": "Baz",
    "description": None,
    "price": 50.2,
    "tax": 10.5,
    "tags": []
}
```

FastAPIは十分に賢いので（実際には、Pydanticが十分に賢い）`description`や`tax`、`tags`はデフォルト値と同じ値を持っているにもかかわらず、明示的に設定されていることを理解しています。（デフォルトから取得するのではなく）

そのため、それらはJSONレスポンスに含まれることになります。

!!! tip "豆知識"
    デフォルト値は`None`だけでなく、なんでも良いことに注意してください。