// You could create an env var MY_NAME with
    $ export MY_NAME="Wade Wilson"

    // Then you could use it with other programs, like
    $ echo "Hello $MY_NAME"

    Hello Wade Wilson
    ```

    </div>

=== "Windows PowerShell"

    <div class="termy">

    ```console
    // Create an env var MY_NAME
    $ $Env:MY_NAME = "Wade Wilson"

    // Use it with other programs, like

from fastapi._compat import PYDANTIC_V2

needs_py39 = pytest.mark.skipif(sys.version_info < (3, 9), reason="requires python3.9+")
needs_py310 = pytest.mark.skipif(
    sys.version_info < (3, 10), reason="requires python3.10+"
)
needs_pydanticv2 = pytest.mark.skipif(not PYDANTIC_V2, reason="requires Pydantic v2")

from .utils import needs_pydanticv1, needs_pydanticv2


class Person:
    def __init__(self, name: str):
        self.name = name


class Pet:
    def __init__(self, owner: Person, name: str):
        self.owner = owner
        self.name = name


@dataclass
class Item:
    name: str
    count: int


class DictablePerson(Person):
    def __iter__(self):

    $ export MY_NAME="Wade Wilson"

    // 然后您可以与其他程序一起使用它，例如
    $ echo "Hello $MY_NAME"

    Hello Wade Wilson
    ```

    </div>

=== "Windows PowerShell"

    <div class="termy">

    ```console
    // 创建一个名为 MY_NAME 的环境变量
    $ $Env:MY_NAME = "Wade Wilson"

    // 与其他程序一起使用它，例如
    $ echo "Hello $Env:MY_NAME"

    Hello Wade Wilson
    ```

    </div>

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

Beachten Sie, das bedeutet: „`one_person` ist eine **Instanz** der Klasse `Person`“.

Es bedeutet nicht: „`one_person` ist die **Klasse** genannt `Person`“.

## Pydantic Modelle

<a href="https://pydantic-docs.helpmanual.io/" class="external-link" target="_blank">Pydantic</a> ist eine Python-Bibliothek für die Validierung von Daten.

    )


async def websocket_request_validation_exception_handler(
    websocket: WebSocket, exc: WebSocketRequestValidationError
) -> None:
    await websocket.close(
        code=WS_1008_POLICY_VIOLATION, reason=jsonable_encoder(exc.errors())

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

লক্ষ্য করুন যে এর মানে হল "`one_person` হল ক্লাস `Person`-এর একটি **ইন্সট্যান্স**।"

এর মানে এটি নয় যে "`one_person` হল **ক্লাস** যাকে বলা হয় `Person`।"

## Pydantic মডেল

[Pydantic](https://docs.pydantic.dev/) হল একটি Python লাইব্রেরি যা ডাটা ভ্যালিডেশন সম্পাদন করে।

আপনি ডাটার "আকার" এট্রিবিউট সহ ক্লাস হিসেবে ঘোষণা করেন।

### Tip olarak Sınıflar

Bir değişkenin tipini bir sınıf ile bildirebilirsiniz.

Diyelim ki  `name` değerine sahip `Person` sınıfınız var:

```Python hl_lines="1-3"
{!../../../docs_src/python_types/tutorial010.py!}
```

Sonra bir değişkeni 'Person' tipinde tanımlayabilirsiniz:

```Python hl_lines="6"
{!../../../docs_src/python_types/tutorial010.py!}
```

### Classes como tipos

Você também pode declarar uma classe como o tipo de uma variável.

Digamos que você tenha uma classe `Person`, com um nome:

```Python hl_lines="1 2 3"
{!../../../docs_src/python_types/tutorial010.py!}
```

Então você pode declarar que uma variável é do tipo `Person`:

```Python hl_lines="6"
{!../../../docs_src/python_types/tutorial010.py!}
```

### Clases como tipos

También puedes declarar una clase como el tipo de una variable.

Digamos que tienes una clase `Person`con un nombre:

```Python hl_lines="1-3"
{!../../../docs_src/python_types/tutorial009.py!}
```

Entonces puedes declarar una variable que sea de tipo `Person`:

```Python hl_lines="6"
{!../../../docs_src/python_types/tutorial009.py!}
```