Zum Beispiel:

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


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

In diesem Fall ist `fluffy` eine Instanz der Klasse `Cat`.

Und um `fluffy` zu erzeugen, rufen Sie `Cat` auf.

Eine Python-Klasse ist also auch ein **Callable**.

Por exemplo:

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


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

Nesse caso,  `fluffy` é uma instância da classe `Cat`.

E para criar `fluffy`, você está "chamando" `Cat`.

Então, uma classe Python também é "chamável".

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

mit einem JSON-Körper:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

dann verarbeitet *Ihre API* die Rechnung und sendet irgendwann später einen Callback-Request an die `callback_url` (die *externe API*):

```

Par exemple :

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


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

Dans ce cas, `fluffy` est une instance de la classe `Cat`.

Et pour créer `fluffy`, vous « appelez » `Cat`.

Donc, une classe Python est aussi un « callable ».

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

з JSON-тілом:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

тоді *ваш API* опрацює рахунок і згодом надішле запит зворотного виклику на `callback_url` ( *зовнішній API* ):

```

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

avec un corps JSON :

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

alors *votre API* traitera la facture et, à un moment ultérieur, enverra une requête de callback à `callback_url` (l’*API externe*) :

```

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

con un JSON body de:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

luego *tu API* procesará la factura y, en algún momento después, enviará un request de callback al `callback_url` (la *API externa*):

```

        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Rick")

```
https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

com um corpo JSON de:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

então *sua API* processará a fatura e, em algum momento posterior, enviará um request de callback para o `callback_url` (a *API externa*):

```

        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 0, .1)
        code ->> function: say_hi(name="Rick", salutation="Mr.")
        function ->> execute: execute function code
        execute ->> code: return the result
    end

    rect rgba(0, 255, 255, .1)
        code ->> function: say_hi(name="Rick")