* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

假设要触发的自定义异常叫作 `UnicornException`。

且需要 FastAPI 实现全局处理该异常。

此时，可以用 `@app.exception_handler()` 添加自定义异常控制器：

```Python hl_lines="5-7  13-18  24"
{!../../docs_src/handling_errors/tutorial003.py!}

```

请求 `/unicorns/yolo` 时，路径操作会触发 `UnicornException`。

但该异常将会被 `unicorn_exception_handler` 处理。

接收到的错误信息清晰明了，HTTP 状态码为 `418`，JSON 内容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}

```

以下のスポンサーになることもできます:

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

```

////

## 执行项目

您可以复制这些代码并按原样使用它。

/// info

事实上，这里的代码只是大多数测试代码的一部分。

///

你可以用 Uvicorn 运行它：


<div class="termy">

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

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

<div class="termy">

```console
$ ADMIN_EMAIL="******@****.***" APP_NAME="ChimichangApp" fastapi run main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip

To set multiple env vars for a single command just separate them with a space, and put them all before the command.

///

  문서에서 보았듯이, FastAPI는 Starlette과 Pydantic 라는 거인의 어깨에 타고 있습니다.

  다음의 스폰서가 될 수 있습니다

  - [Samuel Colvin (Pydantic)](https://github.com/sponsors/samuelcolvin)
  - [Encode (Starlette, Uvicorn)](https://github.com/sponsors/encode)

  ------

///

## Check the automatic API docs

Now, run your app:

<div class="termy">

```console
$ fastapi dev app/main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

And open the docs at <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---