from ._compat import PYDANTIC_V2, PYDANTIC_VERSION, Undefined

_Unset: Any = Undefined


class ParamTypes(Enum):
    query = "query"
    header = "header"
    path = "path"
    cookie = "cookie"


class Param(FieldInfo):
    in_: ParamTypes

    def __init__(
        self,
        default: Any = Undefined,
        *,
        default_factory: Union[Callable[[], Any], None] = _Unset,

=== "Python 3.10+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/cookie_params/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/cookie_params/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/cookie_params/tutorial001_an.py!}
    ```

=== "Python 3.10+ non-Annotated"

    !!! tip

```Python hl_lines="6  11"
{!../../../docs_src/path_params/tutorial003.py!}
```

Otherwise, the path for `/users/{user_id}` would match also for `/users/me`, "thinking" that it's receiving a parameter `user_id` with a value of `"me"`.

Similarly, you cannot redefine a path operation:

```Python hl_lines="6  11"
{!../../../docs_src/path_params/tutorial003b.py!}
```

```Python hl_lines="6  11"
{!../../../docs_src/path_params/tutorial003.py!}
```

Иначе путь для `/users/{user_id}` также будет соответствовать `/users/me`, "подразумевая", что он получает параметр `user_id` со значением `"me"`.

Аналогично, вы не можете переопределить операцию с путем:

```Python hl_lines="6  11"
{!../../../docs_src/path_params/tutorial003b.py!}
```

```Python hl_lines="16"
{!../../../docs_src/path_params/tutorial005.py!}
```

### 查看文档

 API 文档会显示预定义*路径参数*的可用值：

<img src="/img/tutorial/path-params/image03.png">

### 使用 Python _枚举类型_

*路径参数*的值是枚举的元素。

#### 比较*枚举元素*

枚举类 `ModelName` 中的*枚举元素*支持比较操作：

```Python hl_lines="17"
{!../../../docs_src/path_params/tutorial005.py!}
```

#### 获取*枚举值*

```Python hl_lines="16"
{!../../../docs_src/path_params/tutorial005.py!}
```

### Documentation

Les valeurs disponibles pour le *paramètre de chemin* sont bien prédéfinies, la documentation les affiche correctement :

<img src="/img/tutorial/path-params/image03.png">

### Manipuler les *énumérations* Python

=== "Python 3.10+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an.py!}
    ```

=== "Python 3.10+ nicht annotiert"

=== "Python 3.10+"

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params/tutorial002_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```

Bu durumda, `q` fonksiyon parametresi isteğe bağlı olacak ve varsayılan değer olarak `None` alacaktır.

!!! check "Ek bilgi"

=== "Python 3.10+"

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params/tutorial002_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```

In diesem Fall wird der Funktionsparameter `q` optional, und standardmäßig `None` sein.

!!! check

    {!> ../../../docs_src/query_params/tutorial006.py!}
    ```

=== "🐍 3️⃣.1️⃣0️⃣ & 🔛"

    ```Python hl_lines="8"
    {!> ../../../docs_src/query_params/tutorial006_py310.py!}
    ```

👉 💼, 📤 3️⃣ 🔢 🔢:

* `needy`, ✔ `str`.
* `skip`, `int` ⏮️ 🔢 💲 `0`.
* `limit`, 📦 `int`.

!!! tip