你可以在编辑器中连接调试器，例如使用 Visual Studio Code 或 PyCharm。

## 调用 `uvicorn`

在你的 FastAPI 应用中直接导入 `uvicorn` 并运行：

```Python hl_lines="1  15"
{!../../../docs_src/debugging/tutorial001.py!}
```

### 关于 `__name__ == "__main__"`

`__name__ == "__main__"` 的主要目的是使用以下代码调用文件时执行一些代码：

<div class="termy">

```console
$ python myapp.py
```

</div>

而当其它文件导入它时并不会被调用，像这样：

```Python
from myapp import app
```

#### 更多细节

NAME                   ADDRESSES PORT  MATCH DESTINATION
listener/main_internal           0     ALL   Cluster: inbound-vip|8100|http|httpbin.default.svc.cluster.local
listener/main_internal           0     ALL   Cluster: inbound-vip|8000|http|httpbin.default.svc.cluster.local
listener/main_internal           0     ALL   Cluster: encap
listener/main_internal           0     ALL   Cluster: encap

        #  you should specify the map of included schemas.
        #  Additional schemas have original settings apart from the main schema.
        #  The settings are objectTypeTargetList, tableExceptList,
        #  tableTargetList, and columnExceptMap.
        #  They have the same specification as ones of the main schema.
        #  Elements of this map are as below: 
        #    o objectTypeTargetList: (NotRequired - Default 'map:{TABLE;VIEW}')

%{snippet|id=default|file=${project.basedir}/src/main/java/org/apache/maven/lifecycle/providers/DefaultLifecycleProvider.java}

* <<<clean>>> Lifecycle

  <<<clean>>> lifecycle phases are defined with their plugins bindings:

%{snippet|id=clean|file=${project.basedir}/src/main/java/org/apache/maven/lifecycle/providers/CleanLifecycleProvider.java}

* <<<site>>> Lifecycle

# Advanced User Guide

## Additional Features

The main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} should be enough to give you a tour through all the main features of **FastAPI**.

In the next sections you will see other options, configurations, and additional features.

!!! tip
    The next sections are **not necessarily "advanced"**.

    And it's possible that for your use case, the solution is in one of them.

```

</div>

➡️ 👀 ⚫️❔ 🔠 👈 🎛 ⛓:

* `main:app`: 👉 🎏 ❕ ⚙️ Uvicorn, `main` ⛓ 🐍 🕹 📛 "`main`",, 📁 `main.py`. &amp; `app` 📛 🔢 👈 **FastAPI** 🈸.
    * 👆 💪 🌈 👈 `main:app` 🌓 🐍 `import` 📄 💖:

        ```Python
        from main import app
        ```

    * , ❤ `main:app` 🔜 🌓 🐍 `import` 🍕 `from main import app`.
* `--workers`: 🔢 👨‍🏭 🛠️ ⚙️, 🔠 🔜 🏃 Uvicorn 👨‍🏭, 👉 💼, 4️⃣ 👨‍🏭.

    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

Because this file is in the same package, you can use relative imports to import the object `app` from the `main` module (`main.py`):

```Python hl_lines="3"
{!../../../docs_src/app_testing/test_main.py!}
```

...and have the code for the tests just like before.

## Testing: extended example

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>
<font color="#3465A4">INFO    </font> Resolved absolute path <font color="#75507B">/home/user/code/awesomeapp/</font><font color="#AD7FA8">main.py</font>

[19515] [INFO] Application startup complete.
```

</div>


让我们看看每个选项的含义：

* `main:app`：这与 Uvicorn 使用的语法相同，`main` 表示名为"`main`"的 Python 模块，因此是文件 `main.py`。 `app` 是 **FastAPI** 应用程序的变量名称。
     * 你可以想象 `main:app` 相当于一个 Python `import` 语句，例如：

        ```Python
        from main import app
        ```

     * 因此，`main:app` 中的冒号相当于 `from main import app` 中的 Python `import` 部分。