## The main `FastAPI`

Now, let's see the module at `app/main.py`.

Here's where you import and use the class `FastAPI`.

This will be the main file in your application that ties everything together.

And as most of your logic will now live in its own specific module, the main file will be quite simple.

### Import `FastAPI`

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

</div>

!!! note "備考"
    `uvicorn main:app`は以下を示します:

    * `main`: `main.py`ファイル (Python "module")。
    * `app`:  `main.py`内部で作られるobject（`app = FastAPI()`のように記述される）。
    * `--reload`: コードの変更時にサーバーを再起動させる。開発用。

出力には次のような行があります:

```hl_lines="4"

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

</div>

!!! note "참고"
    `uvicorn main:app` 명령은 다음을 의미합니다:

    * `main`: 파일 `main.py` (파이썬 "모듈").
    * `app`: `main.py` 내부의 `app = FastAPI()` 줄에서 생성한 오브젝트.
    * `--reload`: 코드 변경 시 자동으로 서버 재시작. 개발 시에만 사용.

출력되는 줄들 중에는 아래와 같은 내용이 있습니다:

```hl_lines="4"

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

</div>

!!! note "Nota"
    El comando `uvicorn main:app` se refiere a:

    * `main`: el archivo `main.py` (el "módulo" de Python).
    * `app`: el objeto creado dentro de `main.py` con la línea `app = FastAPI()`.
    * `--reload`: hace que el servidor se reinicie cada vez que cambia el código. Úsalo únicamente para desarrollo.

* `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
        ```

RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt

# (1)
COPY ./main.py /code/

# (2)
CMD ["fastapi", "run", "main.py", "--port", "80"]
```

1. Copy the `main.py` file to the `/code` directory directly (without any `./app` directory).

2. Use `fastapi run` to serve your application in the single file `main.py`.

            attribute(DocsType.DOCS_TYPE_ATTRIBUTE, objects.named("gradle-source-folders"))
        }
        val main = sourceSets.main.get()
        main.java.srcDirs.forEach {
            outgoing.artifact(it)
        }
        main.groovy.srcDirs.forEach {
            outgoing.artifact(it)
        }
        main.resources.srcDirs.forEach {
            outgoing.artifact(it)
        }

    /** The key of the configuration. e.g. true */
    String MAIL_SEND_MOCK = "mail.send.mock";

    /** The key of the configuration. e.g. localhost:25 */
    String MAIL_SMTP_SERVER_MAIN_HOST_AND_PORT = "mail.smtp.server.main.host.and.port";

    /** The key of the configuration. e.g. [Test] */
    String MAIL_SUBJECT_TEST_PREFIX = "mail.subject.test.prefix";

    /** The key of the configuration. e.g. root@localhost */

                    }
                """
            )
            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 {

    `Item(**item.dict(), owner_id=user_id)`

## 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 3.9+"

    ```Python hl_lines="7"
    {!> ../../../docs_src/sql_databases/sql_app_py39/main.py!}
    ```

=== "Python 3.8+"