from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None


app = FastAPI()


@app.post("/items/")
async def create_item(item: Item):

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: float = 10.5


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The Bar fighters", "price": 62, "tax": 20.2},
    "baz": {
        "name": "Baz",

### Response Elements

XML response for this API is similar to [AWS STS AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html#API_AssumeRole_ResponseElements)

### Errors

XML error response for this API is similar to [AWS STS AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html#API_AssumeRole_Errors)

## Sample `POST` Request

```

        String str = info.toString();

        // Verify string contains expected elements
        assertNotNull(str);
        assertTrue(str.startsWith("SmbQueryFileBasicInfo["));
        assertTrue(str.contains("createTime="));
        assertTrue(str.contains("lastAccessTime="));
        assertTrue(str.contains("lastWriteTime="));
        assertTrue(str.contains("changeTime="));

```Python hl_lines="1"
async def needy_dependency(fresh_value: Annotated[str, Depends(get_value, use_cache=False)]):
    return {"fresh_value": fresh_value}
```

////

//// tab | Python 3.9+ sin Anotaciones

/// tip | Consejo

Prefiere usar la versión `Annotated` si es posible.

///

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):

from typing import Optional


def get_authorization_scheme_param(
    authorization_header_value: Optional[str],
) -> tuple[str, str]:
    if not authorization_header_value:
        return "", ""
    scheme, _, param = authorization_header_value.partition(" ")

### Response Elements

XML response for this API is similar to [AWS STS AssumeRoleWithWebIdentity](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRoleWithWebIdentity.html#API_AssumeRoleWithWebIdentity_ResponseElements)

### Errors

XML error response for this API is similar to [AWS STS AssumeRoleWithWebIdentity](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRoleWithWebIdentity.html#API_AssumeRoleWithWebIdentity_Errors)

    b: Annotated[float, Body(allow_inf_nan=False)] = 0,
) -> str:
    return "OK"


client = TestClient(app)


@pytest.mark.parametrize(
    "value,code",
    [
        ("-1", 200),
        ("inf", 200),
        ("-inf", 200),
        ("nan", 200),
        ("0", 200),
        ("342", 200),
    ],
)
def test_allow_inf_nan_param_true(value: str, code: int):
    response = client.post(f"/?x={value}")

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009_py39.py!}
```

Использование `Optional[str]` вместо просто `str` позволит редактору кода помочь вам обнаружить ошибки, когда вы предполагаете, что значение всегда `str`, хотя на самом деле оно может быть и `None`.

`Optional[Something]` — это на самом деле сокращение для `Union[Something, None]`, они эквивалентны.

     */
    private String sanitizeForLog(String str) {
        if (str == null) {
            return "null";
        }

        // Truncate long strings
        if (str.length() > 100) {
            str = str.substring(0, 100) + "...";
        }

        // Remove control characters
        return str.replaceAll("[\\x00-\\x1F\\x7F]", "?");
    }

    /**