Boolean indicating if debug tracebacks should be returned on server
                errors.

                Read more in the
                [Starlette docs for Applications](https://www.starlette.io/applications/#instantiating-the-application).
                """
            ),
        ] = False,
        routes: Annotated[
            Optional[List[BaseRoute]],
            Doc(
                """

Sie sehen die automatische API-Dokumentation für die Hauptanwendung, welche nur deren eigene _Pfadoperationen_ anzeigt:

<img src="/img/tutorial/sub-applications/image01.png">

Öffnen Sie dann die Dokumentation für die Unteranwendung unter <a href="http://127.0.0.1:8000/subapi/docs" class="external-link" target="_blank">http://127.0.0.1:8000/subapi/docs</a>.

<img src="/img/tutorial/sub-applications/image01.png">

و سپس اسناد زیر برنامه را در آدرس <a href="http://127.0.0.1:8000/subapi/docs" class="external-link" target="_blank">http://127.0.0.1:8000/subapi/docs</a>. باز کنید.

اسناد API خودکار برای زیر برنامه را خواهید دید، که فقط شامل path operations خود می شود، همه در زیر مسیر `/subapi` قرار دارند:

<img src="/img/tutorial/sub-applications/image02.png">

* 还有一个子目录 `app/internal/` 包含另一个 `__init__.py` 文件，因此它是又一个「Python 子包」：`app.internal`。
* `app/internal/admin.py` 是另一个子模块：`app.internal.admin`。

<img src="https://fastapi.tiangolo.com/img/tutorial/bigger-applications/package.svg">

带有注释的同一文件结构：

```
.
├── app                  # 「app」是一个 Python 包
│   ├── __init__.py      # 这个文件使「app」成为一个 Python 包
│   ├── main.py          # 「main」模块，例如 import app.main

下图显示的是主应用 API 文档，只包括其自有的*路径操作*。

<img src="/img/tutorial/sub-applications/image01.png">

然后查看子应用文档 <a href="http://127.0.0.1:8000/subapi/docs" class="external-link" target="_blank">http://127.0.0.1:8000/subapi/docs。</a>

下图显示的是子应用的 API 文档，也是只包括其自有的*路径操作*，所有这些路径操作都在 `/subapi` 子路径前缀下。

<img src="/img/tutorial/sub-applications/image02.png">

两个用户界面都可以正常运行，因为浏览器能够与每个指定的应用或子应用会话。

### 技术细节：`root_path`

# Sub Applications - Mounts

If you need to have two independent FastAPI applications, with their own independent OpenAPI and their own docs UIs, you can have a main app and "mount" one (or more) sub-application(s).

## Mounting a **FastAPI** application

"Mounting" means adding a completely "independent" application in a specific path, that then takes care of handling everything under that path, with the _path operations_ declared in that sub-application.

# Bigger Applications - Multiple Files

If you are building an application or a web API, it's rarely the case that you can put everything in a single file.

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure

Let's say you have a file structure like this:

```

👆 🔜 👀 🏧 🛠️ 🩺 👑 📱, 🔌 🕴 🚮 👍 _➡ 🛠️_:

<img src="/img/tutorial/sub-applications/image01.png">

&amp; ⤴️, 📂 🩺 🎧-🈸, <a href="http://127.0.0.1:8000/subapi/docs" class="external-link" target="_blank">http://127.0.0.1:8000/subapi/docs</a>.

👆 🔜 👀 🏧 🛠️ 🩺 🎧-🈸, ✅ 🕴 🚮 👍 _➡ 🛠️_, 🌐 🔽 ☑ 🎧-➡ 🔡 `/subapi`:

<img src="/img/tutorial/sub-applications/image02.png">

Você verá a documentação automática da API para a aplicação principal, incluindo apenas suas próprias _operações de rota_:

<img src="/img/tutorial/sub-applications/image01.png">

E então, abra a documentação para a sub-aplicação, em <a href="http://127.0.0.1:8000/subapi/docs" class="external-link" target="_blank">http://127.0.0.1:8000/subapi/docs</a>.

* 📤 📁 `app/internal/` ⏮️ ➕1️⃣ 📁 `__init__.py`, ⚫️ ➕1️⃣ "🐍 📦": `app.internal`.
*  & 📁 `app/internal/admin.py` ➕1️⃣ 🔁: `app.internal.admin`.

<img src="/img/tutorial/bigger-applications/package.svg">

🎏 📁 📊 ⏮️ 🏤:

```
.
├── app                  # "app" is a Python package
│   ├── __init__.py      # this file makes "app" a "Python package"