# Primeiros Passos

O arquivo FastAPI mais simples pode se parecer com:

```Python
{!../../../docs_src/first_steps/tutorial001.py!}
```

Copie o conteúdo para um arquivo `main.py`.

Execute o servidor:

<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)

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

* Ezután kattints az "Execute" gompra, a felhasználói felület kommunikálni fog az API-oddal. Elküldi a paramétereket és a visszakapott választ megmutatja a képernyődön.

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

* Luego haz click en el botón de "Execute". La interfaz de usuario se comunicará con tu API, enviará los parámetros y recibirá los resultados para mostrarlos en pantalla:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

- "Try it out" বাটনে চাপুন, এটি আপনাকে পেরামিটারগুলো পূরণ করতে এবং API এর সাথে সরাসরি ক্রিয়া-কলাপ করতে দিবে:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

- তারপরে "Execute" বাটনে চাপুন, ব্যবহারকারীর ইন্টারফেস আপনার API এর সাথে যোগাযোগ করবে, পেরামিটার পাঠাবে, ফলাফলগুলি পাবে এবং সেগুলি পর্রদায় দেখাবে:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

```Python hl_lines="6-7"
{!../../../docs_src/path_params/tutorial001.py!}
```

La valeur du paramètre `item_id` sera transmise à la fonction dans l'argument `item_id`.

Donc, si vous exécutez cet exemple et allez sur <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>,
vous verrez comme réponse :

```JSON
{"item_id":"foo"}
```

```Python
{!../../../docs_src/security/tutorial001.py!}
```

## Execute-o

!!! info "informação"
	Primeiro, instale <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

	Ex: `pip install python-multipart`.

	Isso ocorre porque o **OAuth2** usa "dados de um formulário" para mandar o **username** e **senha**.

Execute esse exemplo com:

<div class="termy">

```console

        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="2  6  10"
    {!> ../../../docs_src/security/tutorial006.py!}
    ```

When you try to open the URL for the first time (or click the "Execute" button in the docs) the browser will ask you for your username and password:

<img src="/img/tutorial/security/image12.png">

## Check the username

Here's a more complete example.

    ```Python hl_lines="2  6  10"
    {!> ../../../docs_src/security/tutorial006.py!}
    ```

Wenn Sie versuchen, die URL zum ersten Mal zu öffnen (oder in der Dokumentation auf den Button „Execute“ zu klicken), wird der Browser Sie nach Ihrem Benutzernamen und Passwort fragen:

<img src="/img/tutorial/security/image12.png">

## Den Benutzernamen überprüfen

Hier ist ein vollständigeres Beispiel.

* 在*路径操作*的依赖项中使用 `security`
* 返回类型为 `HTTPBasicCredentials` 的对象：
    * 包含发送的 `username` 与 `password`

```Python hl_lines="2  6  10"
{!../../../docs_src/security/tutorial006.py!}
```

第一次打开 URL（或在 API 文档中点击 **Execute** 按钮）时，浏览器要求输入用户名与密码：

<img src="/img/tutorial/security/image12.png">

## 检查用户名

以下是更完整的示例。

使用依赖项检查用户名与密码是否正确。