```

=== "Python 3.8+"

    ```Python hl_lines="14"
    {!> ../../../docs_src/body_nested_models/tutorial002.py!}
    ```

## Set-Typen

Aber dann denken wir darüber nach und stellen fest, dass sich die Tags nicht wiederholen sollen, es sollen eindeutige Strings sein.

Python hat einen Datentyp speziell für Mengen eindeutiger Dinge: das <abbr title="Menge">`set`</abbr>.

You will also get autocompletion for the payload to send:

<img src="/img/tutorial/generate-clients/image03.png">

!!! tip
    Notice the autocompletion for `name` and `price`, that was defined in the FastAPI application, in the `Item` model.

You will have inline errors for the data that you send:

<img src="/img/tutorial/generate-clients/image04.png">

The response object will also have autocompletion:

### Check the docs UI

But here's the fun part. ✨

The "official" way to access the app would be through the proxy with the path prefix that we defined. So, as we would expect, if you try the docs UI served by Uvicorn directly, without the path prefix in the URL, it won't work, because it expects to be accessed through the proxy.

        self.scope_str: Annotated[
            str,
            Doc(
                """
                All the scopes required by all the dependencies in a single string
                separated by spaces, as defined in the OAuth2 specification.
                """
            ),

    * This will be used by the **automatic docs**.
    * It will also be used by automatic client code generation tools.

But most importantly:

* It will **limit and filter** the output data to what is defined in the return type.
    * This is particularly important for **security**, we'll see more of that below.

## `response_model` Parameter

### TLS Handshake Start

The browser would then communicate with that IP address on **port 443** (the HTTPS port).

The first part of the communication is just to establish the connection between the client and the server and to decide the cryptographic keys they will use, etc.

<img src="/img/deployment/https/https02.svg">

This interaction between the client and the server to establish the TLS connection is called the **TLS handshake**.

I'll tell you a bit more about these **concepts** here, and that would hopefully give you the **intuition** you would need to decide how to deploy your API in very different environments, possibly even in **future** ones that don't exist yet.

By considering these concepts, you will be able to **evaluate and design** the best way to deploy **your own APIs**.

As an example, let's take this function:

```Python hl_lines="1  4"
{!../../../docs_src/python_types/tutorial009c.py!}
```

The parameter `name` is defined as `Optional[str]`, but it is **not optional**, you cannot call the function without the parameter:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

Então, quando é sua vez, você faz o trabalho "produtivo" de verdade, você processa o menu, decide o que quer, pega a escolha de seu _crush_ :heart_eyes:, paga, verifica se entregou o valor correto em dinheiro ou cartão de crédito, verifica se foi cobrado corretamente, verifica se seu pedido está correto etc.

!!! tip "Tipp"
    Denken Sie daran, dass Sie in den meisten Fällen, wenn etwas erforderlich ist, einfach den Defaultwert weglassen können. Sie müssen also normalerweise `...` nicht verwenden.

## Query-Parameter-Liste / Mehrere Werte