This utility function will:

* Connect to a **Couchbase** cluster (that might be a single machine).
    * Set defaults for timeouts.
* Authenticate in the cluster.
* Get a `Bucket` instance.
    * Set defaults for timeouts.
* Return it.

```Python hl_lines="12-21"
{!../../../docs_src/nosql_databases/tutorial001.py!}
```

## Create Pydantic models

{!../../../docs_src/python_types/tutorial010.py!}
```

And then, again, you get all the editor support:

<img src="/img/python-types/image06.png">

Notice that this means "`one_person` is an **instance** of the class `Person`".

It doesn't mean "`one_person` is the **class** called `Person`".

## Pydantic models

        pass

    class MyModel(BaseModel):
        dt_field: safe_datetime

    instance = MyModel(dt_field=safe_datetime.now())

    encoded_instance = jsonable_encoder(
        instance, custom_encoder={safe_datetime: lambda o: o.isoformat()}
    )
    assert encoded_instance["dt_field"] == instance.dt_field.isoformat()


def test_custom_enum_encoders():
    def custom_enum_encoder(v: Enum):

You can create the *path operations* for that module using `APIRouter`.

### Import `APIRouter`

You import it and create an "instance" the same way you would with the class `FastAPI`:

```Python hl_lines="1  3" title="app/routers/users.py"
{!../../../docs_src/bigger_applications/app/routers/users.py!}
```

### *Path operations* with `APIRouter`

        if (
            key in main_dict
            and isinstance(main_dict[key], dict)
            and isinstance(value, dict)
        ):
            deep_dict_update(main_dict[key], value)
        elif (
            key in main_dict
            and isinstance(main_dict[key], list)
            and isinstance(update_dict[key], list)
        ):

    assert response.status_code == expected_status
    assert response.json() == expected_response


def test_route_classes():
    routes = {}
    for r in app.router.routes:
        assert isinstance(r, Route)
        routes[r.path] = r
    assert getattr(routes["/a/"], "x_type") == "A"  # noqa: B009
    assert getattr(routes["/a/b/"], "x_type") == "B"  # noqa: B009

* Intégration Python facile avec **Jupyter Kernels** pour le développement à distance ou intra-Docker avec des extensions comme Atom Hydrogen ou Visual Studio Code Jupyter.
* Frontend **Vue** :
    * Généré avec Vue CLI.
    * Gestion de l'**Authentification JWT**.
    * Page de connexion.

    * Bởi vì các cấu trúc dữ liệu của Pydantic chỉ là các instances của class bạn định nghĩa; auto-completion, linting, mypy và trực giác của bạn nên làm việc riêng biệt với những dữ liệu mà bạn đã validate.
* Validate **các cấu trúc phức tạp**:

### Étape 2 : créer une "instance" `FastAPI`

```Python hl_lines="3"
{!../../../docs_src/first_steps/tutorial001.py!}
```

Ici la variable `app` sera une "instance" de la classe `FastAPI`.

Ce sera le point principal d'interaction pour créer toute votre API.

then it is a "callable".

## Classes as dependencies

You might notice that to create an instance of a Python class, you use that same syntax.

For example:

```Python
class Cat:
    def __init__(self, name: str):
        self.name = name


fluffy = Cat(name="Mr Fluffy")
```

In this case, `fluffy` is an instance of the class `Cat`.

And to create `fluffy`, you are "calling" `Cat`.