```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/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*

from typing import Any, Callable, Dict, List, Optional, Sequence, Union

from fastapi import params
from fastapi._compat import Undefined
from fastapi.openapi.models import Example
from typing_extensions import Annotated, Doc, deprecated

_Unset: Any = Undefined


def Path(  # noqa: N802
    default: Annotated[
        Any,
        Doc(
            """
            Default value if the parameter field is not set.

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params_str_validations/tutorial011.py!}
    ```

=== "🐍 3️⃣.9️⃣ & 🔛"

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params_str_validations/tutorial011_py39.py!}
    ```

=== "🐍 3️⃣.1️⃣0️⃣ & 🔛"

    ```Python hl_lines="7"
    {!> ../../../docs_src/query_params_str_validations/tutorial011_py310.py!}
    ```

⤴️, ⏮️ 📛 💖:

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,

def get_client():
    from docs_src.query_params_str_validations.tutorial010_an import app

    client = TestClient(app)
    return client


def test_query_params_str_validations_no_query(client: TestClient):
    response = client.get("/items/")
    assert response.status_code == 200
    assert response.json() == {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}

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