# 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.

* `main:app`: Das ist die gleiche Syntax, die auch von Uvicorn verwendet wird. `main` bedeutet das Python-Modul mit dem Namen `main`, also eine Datei `main.py`. Und `app` ist der Name der Variable, welche die **FastAPI**-Anwendung ist.
    * Stellen Sie sich einfach vor, dass `main:app` einer Python-`import`-Anweisung wie der folgenden entspricht:

        ```Python
        from main import app
        ```

[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。

                    }
                """
            )
            withDirectory("v1/src/main").v1()
            withDirectory("v2/src/main").v2()
            val sourceRoots = if (File(withDirectory("v2/src/main"), "java").exists()) {
                "v2/src/main/java"
            } else {
                "v2/src/main/kotlin"
            }
            withDirectory("binary-compatibility").apply {

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note
    La commande `uvicorn main:app` fait référence à :

    * `main` : le fichier `main.py` (le module Python).
    * `app` : l'objet créé dans `main.py` via la ligne `app = FastAPI()`.
    * `--reload` : l'option disant à uvicorn de redémarrer le serveur à chaque changement du code. À ne pas utiliser en production !

## Code Examples

[Using minio-go library](https://github.com/minio/minio/blob/master/docs/extensions/s3zip/examples/minio-go/main.go)
[Using AWS JS SDK v2](https://github.com/minio/minio/blob/master/docs/extensions/s3zip/examples/aws-js/main.js)
[Using boto3](https://github.com/minio/minio/blob/master/docs/extensions/s3zip/examples/boto3/main.py)

## Requirements and limits

See here [1] on how to compile for your platform and here [2] how libraries
follow Jansi's directory and filename conventions.

[1] https://github.com/fusesource/jansi/tree/master/src/main/native

## Main **FastAPI** app

And now in the file `sql_app/main.py` let's integrate and use all the other parts we created before.

### Create the database tables

In a very simplistic way create the database tables:

```Python hl_lines="9-11"
{!../../../docs_src/sql_databases_peewee/sql_app/main.py!}
```

### Create a dependency

With **FastAPI** you can take the advantage of concurrency that is very common for web development (the same main attraction of NodeJS).

But you can also exploit the benefits of parallelism and multiprocessing (having multiple processes running in parallel) for **CPU bound** workloads like those in Machine Learning systems.

```Python hl_lines="48-52"
{!../../../docs_src/websockets/tutorial001.py!}
```

👆 💪 📨 & 📨 💱, ✍, & 🎻 💽.

## 🔄 ⚫️

🚥 👆 📁 📛 `main.py`, 🏃 👆 🈸 ⏮️:

<div class="termy">

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

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

</div>