再一次，可以把 `dataclasses` 与标准类型注解一起使用；

8. 注意，*路径操作函数*使用的是普通函数，不是异步函数；

    与往常一样，在 FastAPI 中，可以按需组合普通函数与异步函数；

    如果不清楚何时使用异步函数或普通函数，请参阅**急不可待？**一节中对 <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank" class="internal-link">`async` 与 `await`</a> 的说明；

9. *路径操作函数*返回的不是数据类（虽然它可以返回数据类），而是返回内含数据的字典列表；

    FastAPI 使用（包含数据类的） `response_model` 参数转换响应。

把 `dataclasses` 与其它类型注解组合在一起，可以组成不同形式的复杂数据结构。

---

Again, these are very technical details that would probably be useful if you came searching for them.

      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and

produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these conditions:

    a) The work must carry prominent notices stating that you modified
    it, and giving a relevant date.

    b) The work must carry prominent notices stating that it is
    released under this License and any conditions added under section

    return {"item_id": item_id, "q": q}
```

**Примітка**:

Стикнувшись з проблемами, не зайвим буде ознайомитися з розділом _"In a hurry?"_ про <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` та `await` у документації</a>.

</details>

### Запустіть

Запустіть server з:

<div class="termy">

```console

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

**Note**:

If you don't know, check the _"In a hurry?"_ section about <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` and `await` in the docs</a>.

</details>

### Run it

Run the server with:

<div class="termy">

```console
$ fastapi dev main.py

async def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

**Not**:

Eğer bu konu hakkında bilginiz yoksa <a href="https://fastapi.tiangolo.com/tr/async/#in-a-hurry" target="_blank">`async` ve `await`</a> dokümantasyonundaki _"Aceleniz mi var?"_ kısmını kontrol edebilirsiniz.

</details>

### Kodu Çalıştıralım

Sunucuyu aşağıdaki komutla çalıştıralım:

async def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

**🗒**:

🚥 👆 🚫 💭, ✅ _"🏃 ❓" _ 📄 🔃 <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` &amp; `await` 🩺</a>.

</details>

### 🏃 ⚫️

🏃 💽 ⏮️:

<div class="termy">

```console
$ uvicorn main:app --reload

        // TODO: Ideally, we should get the substitutor from the candidate. But it seems there is no way to get the substitutor from the
        //  candidate, `Candidate.substitutor` is not complete. maybe we can carry over the final substitutor if it's available from
        //  body resolve phase?
        val substitutor = when (fir) {
            is FirQualifiedAccessExpression -> fir.createSubstitutorFromTypeArguments(targetSymbol)

It doesn't matter. **FastAPI** will know what to do.

!!! note
    If you don't know, check the [Async: *"In a hurry?"*](../../async.md#in-a-hurry){.internal-link target=_blank} section about `async` and `await` in the docs.

## Integrated with OpenAPI