// 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 .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):

### 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!}
```

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

Lưu ý rằng, điều này có nghĩa rằng "`one_person`" là một **thực thể** của lớp `Person`.

Nó không có nghĩa "`one_person`" là một **lớp** gọi là `Person`.

## Pydantic models

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> là một thư viện Python để validate dữ liệu hiệu năng cao.

    They are more relevant for older versions, before OpenAPI 3.1.0 was available.

    You can consider this a brief OpenAPI and JSON Schema **history lesson**. 🤓

!!! warning
    These are very technical details about the standards **JSON Schema** and **OpenAPI**.

---

Here's how to help others with questions (in discussions or issues):

### Understand the question

* Check if you can understand what is the **purpose** and use case of the person asking.

* Then check if the question (the vast majority are questions) is **clear**.

### 🎓 🆎

👆 💪 📣 🎓 🆎 🔢.

➡️ 💬 👆 ✔️ 🎓 `Person`, ⏮️ 📛:

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

⤴️ 👆 💪 📣 🔢 🆎 `Person`:

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

& ⤴️, 🔄, 👆 🤚 🌐 👨‍🎨 🐕‍🦺:

<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

<a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a> is a Python library to perform data validation.

You declare the "shape" of the data as classes with attributes.

### Класи як типи

Ви також можете оголосити клас як тип змінної.

Скажімо, у вас є клас `Person` з імʼям:

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

Потім ви можете оголосити змінну типу `Person`:

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

## Running on Startup

In most cases, when you create a web API, you want it to be **always running**, uninterrupted, so that your clients can always access it. This is of course, unless you have a specific reason why you want it to run only in certain situations, but most of the time you want it constantly running and **available**.

### In a Remote Server