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

**Note**:

If you don't know, check the _"In a hurry?"_ section about [`async` and `await` in the docs](https://fastapi.tiangolo.com/async/#in-a-hurry).

</details>

### Run it

Run the server with:

<div class="termy">

```console
$ fastapi dev

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

**注意**：

如果你不確定，請查看文件中 _"In a hurry?"_ 章節的[關於文件中的 `async` 與 `await`](https://fastapi.tiangolo.com/zh-hant/async/#in-a-hurry)。

</details>

### 運行 { #run-it }

使用以下指令運行伺服器：

<div class="termy">

```console
$ fastapi dev

      future = null;
      while (next != null) {
        @RetainedLocalRef Listener curr = next;
        next = next.next;
        /*
         * requireNonNull is safe because the listener stack never contains TOMBSTONE until after
         * clearListeners.
         */
        Runnable task = requireNonNull(curr.task);
        if (task instanceof DelegatingToFuture) {

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

**Note**:

If you don't know, check the _"In a hurry?"_ section about [`async` and `await` in the docs](https://fastapi.tiangolo.com/async/#in-a-hurry).

</details>

### Run it { #run-it }

Run the server with:

<div class="termy">

```console
$ fastapi dev

      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

      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

      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

      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

# Рівночасність і async / await { #concurrency-and-async-await }

Деталі щодо синтаксису `async def` для функцій операції шляху і деякі відомості про асинхронний код, рівночасність і паралелізм.

## Поспішаєте? { #in-a-hurry }

<abbr title="too long; didn't read - занадто довго; не читав"><strong>TL;DR:</strong></abbr>

Якщо ви використовуєте сторонні бібліотеки, які вимагають виклику з `await`, наприклад:

```Python
results = await some_library()
```

      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