}).orElse(new HighlightInfo());
    }

    protected void updateHighlightInfo(final HighlightInfo highlightInfo, final int width) {
        if (width < TABLET_WIDTH) {
            float ratio = (float) width / (float) TABLET_WIDTH;
            if (ratio < 0.5) {
                ratio = 0.5f;
            }
            highlightInfo.fragmentSize((int) (highlightInfo.getFragmentSize() * ratio));
        }
    }

```Python hl_lines="9  11-12"
{!> ../../docs_src/response_model/tutorial004_py310.py!}
```

////

* `description: Union[str, None] = None` (⚖️ `str | None = None` 🐍 3️⃣.1️⃣0️⃣) ✔️ 🔢 `None`.
* `tax: float = 10.5` ✔️ 🔢 `10.5`.
* `tags: List[str] = []` 🔢 🛁 📇: `[]`.

✋️ 👆 💪 💚 🚫 👫 ⚪️➡️ 🏁 🚥 👫 🚫 🤙 🏪.

🖼, 🚥 👆 ✔️ 🏷 ⏮️ 📚 📦 🔢 ☁ 💽, ✋️ 👆 🚫 💚 📨 📶 📏 🎻 📨 🌕 🔢 💲.

func (b *BucketMetadata) SetCreatedAt(createdAt time.Time) {
	if b.Created.IsZero() {
		b.Created = UTCNow()
	}
	if !createdAt.IsZero() {
		b.Created = createdAt.UTC()
	}
}

// Load - loads the metadata of bucket by name from ObjectLayer api.
// If an error is returned the returned metadata will be default initialized.
func readBucketMetadata(ctx context.Context, api ObjectLayer, name string) (BucketMetadata, error) {

                            "name": "item_id",
                            "in": "path",
                        }
                    ],
                }
            },
            "/path/float/{item_id}": {
                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",

////

Die Funktionsparameter werden wie folgt erkannt:

* Wenn der Parameter auch im **Pfad** deklariert wurde, wird er als Pfad-Parameter interpretiert.
* Wenn der Parameter ein **einfacher Typ** ist (wie `int`, `float`, `str`, `bool`, usw.), wird er als **Query**-Parameter interpretiert.
* Wenn der Parameter vom Typ eines **Pydantic-Modells** ist, wird er als Request**body** interpretiert.

/// note | "Hinweis"

```

////

//// tab | Python 3.8+

```Python hl_lines="18"
{!> ../../docs_src/body/tutorial004.py!}
```

////

函数参数按如下规则进行识别：

- **路径**中声明了相同参数的参数，是路径参数
- 类型是（`int`、`float`、`str`、`bool` 等）**单类型**的参数，是**查询**参数
- 类型是 **Pydantic 模型**的参数，是**请求体**

/// note | "笔记"

因为默认值是 `None`， FastAPI 会把 `q` 当作可选参数。

FastAPI 不使用 `Optional[str]` 中的 `Optional`， 但 `Optional` 可以让编辑器提供更好的支持，并检测错误。

```

Os parâmetros da função serão reconhecidos conforme abaixo:

* Se o parâmetro também é declarado na **rota**, será utilizado como um parâmetro de rota.
* Se o parâmetro é de um **tipo único** (como `int`, `float`, `str`, `bool`, etc) será interpretado como um parâmetro de **consulta**.
* Se o parâmetro é declarado como um **modelo Pydantic**, será interpretado como o **corpo** da requisição.

/// note | "Observação"

	}

	switch funcName {
	case aggFnCount:
		// For all non-null values, the count is incremented.
		e.aggregate.runningCount++

	case aggFnAvg, aggFnSum:
		e.aggregate.runningCount++
		// Convert to float.
		f, ok := argVal.ToFloat()
		if !ok {
			return fmt.Errorf("Could not convert value %v (%s) to a number", argVal.value, argVal.GetTypeString())
		}
		argVal.setFloat(f)

    "${app_commands[@]}" \
    "${residual_args[@]}"
    
  local exit_code=$?
  if is_cygwin; then
    stty icanon echo > /dev/null 2>&1
  fi
  exit $exit_code
}

# Loads a configuration file full of default command line options for this script.
loadConfigFile() {
  cat "$1" | sed '/^\#/d'
}

###  ------------------------------- ###
###  Start of customized settings    ###

```Python hl_lines="4  9-12  25-27"
from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):