import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture
def client():
    from docs_src.body.tutorial001_py310 import app

    client = TestClient(app)
    return client


@needs_py310
def test_body_float(client: TestClient):
    response = client.post("/items/", json={"name": "Foo", "price": 50.5})

Das bedeutet auch, dass Sie in Python 3.10 `Something | None` verwenden können:

//// tab | Python 3.10+

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009.py!}
```

////

//// tab | Python 3.8+ Alternative

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009b.py!}
```

////

//// tab | Python 3.10 і вище

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

////

#### Generic типи

Ці типи, які приймають параметри типу у квадратних дужках, називаються **Generic types** or **Generics**, наприклад:

//// tab | Python 3.8 і вище

# 查询参数和字符串校验

**FastAPI** 允许你为参数声明额外的信息和校验。

让我们以下面的应用程序为例：

//// tab | Python 3.10+

```Python hl_lines="7"
{!> ../../docs_src/query_params_str_validations/tutorial001_py310.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="9"
{!> ../../docs_src/query_params_str_validations/tutorial001.py!}
```

////

查询参数 `q` 的类型为 `str`，默认值为 `None`，因此它是可选的。

## 额外的校验

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009b.py!}
```

////

//// tab | 🐍 3️⃣.1️⃣0️⃣ & 🔛

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

////

#### ⚙️ `Union` ⚖️ `Optional`

🚥 👆 ⚙️ 🐍 ⏬ 🔛 3️⃣.1️⃣0️⃣, 📥 💁‍♂ ⚪️➡️ 👇 📶 **🤔** ☝ 🎑:

* 👶 ❎ ⚙️ `Optional[SomeType]`
* ↩️ 👶 **⚙️ `Union[SomeType, None]`** 👶.