```

!!! tip
    The syntax `{"name", "description"}` creates a `set` with those two values.

    It is equivalent to `set(["name", "description"])`.

#### Using `list`s instead of `set`s

If you forget to use a `set` and use a `list` or `tuple` instead, FastAPI will still convert it to a `set` and it will work correctly:

=== "Python 3.10+"

    ```Python hl_lines="29  35"

    {!> ../../../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>.

Deklarieren wir also `tags` als Set von Strings.

=== "Python 3.10+"

    ```Python hl_lines="12"

Зверніть увагу, що змінна `item` є одним із елементів у списку `items`.

І все ж редактор знає, що це `str`, і надає підтримку для цього.

#### Tuple and Set (кортеж та набір)

Ви повинні зробити те ж саме, щоб оголосити `tuple` і `set`:

=== "Python 3.8 і вище"

    ```Python hl_lines="1  4"
    {!> ../../../docs_src/python_types/tutorial007.py!}
    ```

=== "Python 3.9 і вище"

#### `Tuple` и `Set`

Вы бы сделали то же самое, чтобы объявить `tuple` и `set`:

```Python hl_lines="1  4"
{!../../../docs_src/python_types/tutorial007.py!}
```

Это означает:

* Переменная `items_t` является `tuple` с 3 элементами: `int`, другим `int` и `str`.
* Переменная `items_s` является `set` и каждый элемент имеет тип `bytes`.

#### `Dict`

                header), `HTTPBasic` will automatically cancel the request and send the
                client an error.

                If `auto_error` is set to `False`, when the HTTP Basic authentication
                is not available, instead of erroring out, the dependency result will
                be `None`.

                OAuth2 authentication, it will automatically cancel the request and
                send the client an error.

                If `auto_error` is set to `False`, when the HTTP Authorization header
                is not available, instead of erroring out, the dependency result will
                be `None`.

    Find ways to get great performance.

    Along with Hug (as Hug is based on Falcon) inspired **FastAPI** to declare a `response` parameter in functions.

    Although in FastAPI it's optional, and is used mainly to set headers, cookies, and alternative status codes.

### <a href="https://moltenframework.com/" class="external-link" target="_blank">Molten</a>

## Developing

If you already cloned the <a href="https://github.com/tiangolo/fastapi" class="external-link" target="_blank">fastapi repository</a> and you want to deep dive in the code, here are some guidelines to set up your environment.

### Virtual environment with `venv`

You can create an isolated virtual local environment in a directory using Python's `venv` module. Let's do this in the cloned repository (where the `requirements.txt` is):

    "root_path": "/api/v1"
}
```

### Setting the `root_path` in the FastAPI app

Alternatively, if you don't have a way to provide a command line option like `--root-path` or equivalent, you can set the `root_path` parameter when creating your FastAPI app:

```Python hl_lines="3"
{!../../../docs_src/behind_a_proxy/tutorial002.py!}
```

Notice that the variable `item` is one of the elements in the list `items`.

And still, the editor knows it is a `str`, and provides support for that.

#### Tuple and Set

You would do the same to declare `tuple`s and `set`s:

=== "Python 3.9+"

    ```Python hl_lines="1"
    {!> ../../../docs_src/python_types/tutorial007_py39.py!}
    ```

=== "Python 3.8+"