* Puedes obtener metadatos del archivo subido.
* Tiene una interfaz `async` <a href="https://docs.python.org/3/glossary.html#term-file-like-object" class="external-link" target="_blank">parecida a un archivo</a>.
* Expone un objeto Python real <a href="https://docs.python.org/3/library/tempfile.html#tempfile.SpooledTemporaryFile" class="external-link" target="_blank">`SpooledTemporaryFile`</a> que puedes pasar directamente a otros paquetes que esperan un objeto parecido a un archivo.

* 这种方式更适于处理图像、视频、二进制文件等大型文件，好处是不会占用所有内存；
* 可获取上传文件的元数据；
* 自带 <a href="https://docs.python.org/zh-cn/3/glossary.html#term-file-like-object" class="external-link" target="_blank">file-like</a> `async` 接口；
* 暴露的 Python <a href="https://docs.python.org/zh-cn/3/library/tempfile.html#tempfile.SpooledTemporaryFile" class="external-link" target="_blank">`SpooledTemporaryFile`</a> 对象，可直接传递给其他预期「file-like」对象的库。

### `UploadFile`

`UploadFile` 的属性如下：

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Image(BaseModel):
    url: str
    name: str


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()
    image: Image | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel as BaseModelV2
from pydantic.v1 import BaseModel


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


class ItemV2(BaseModelV2):
    name: str
    description: Union[str, None] = None
    size: float


app = FastAPI()


@app.post("/items/", response_model=ItemV2)

import common.Os
import jetbrains.buildServer.configs.kotlin.BuildType
import model.Stage

open class BaseGradleBuildType(
    open val stage: Stage? = null,
    open val failStage: Boolean = true,
    init: BaseGradleBuildType.() -> Unit = {},
) : BuildType() {
    init {
        this.init()
    }
}

open class OsAwareBaseGradleBuildType(
    val os: Os,
    override val stage: Stage? = null,

          .put(NullPointerException.class, e -> e instanceof NullPointerException)
          .put(NumberFormatException.class, e -> e instanceof NumberFormatException)
          .put(RuntimeException.class, e -> e instanceof RuntimeException)
          .put(TimeoutException.class, e -> e instanceof TimeoutException)

///

//// tab | `pip`

<div class="termy">

```console
$ pip install "fastapi[standard]"

---> 100%
```

</div>

////

//// tab | `uv`

If you have <a href="https://github.com/astral-sh/uv" class="external-link" target="_blank">`uv`</a>:

<div class="termy">

```console
$ uv pip install "fastapi[standard]"
---> 100%
```

import org.dbflute.dbway.DBDef;
import org.dbflute.util.DfTypeUtil;

/**
 * @author ESFlute (using FreeGen)
 */
public class ElevateWordDbm extends AbstractDBMeta {

    protected static final Class<?> suppressUnusedImportLocalDateTime = LocalDateTime.class;

    // ===================================================================================

import org.dbflute.dbway.DBDef;
import org.dbflute.util.DfTypeUtil;

/**
 * @author ESFlute (using FreeGen)
 */
public class ClickLogDbm extends AbstractDBMeta {

    protected static final Class<?> suppressUnusedImportLocalDateTime = LocalDateTime.class;

    // ===================================================================================

## A "callable" instance { #a-callable-instance }

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

To do that, we declare a method `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}