# `UploadFile` class

You can define *path operation function* parameters to be of the type `UploadFile` to receive files from the request.

You can import it directly from `fastapi`:

```python
from fastapi import UploadFile
```

::: fastapi.UploadFile
    options:
        members:
            - file
            - filename
            - size
            - headers
            - content_type
            - read

from starlette.datastructures import UploadFile as StarletteUploadFile
from typing_extensions import Annotated, Doc


class UploadFile(StarletteUploadFile):
    """
    A file uploaded in a request.

    Define it as a *path operation function* (or dependency) parameter.

    If you are using a regular `def` function, you can use the `upload_file.file`

Mas há muitos casos em que você pode se beneficiar do uso de `UploadFile`.

## Parâmetros de Arquivo com `UploadFile`

Defina um parâmetro de arquivo com um tipo de `UploadFile`:

{* ../../docs_src/request_files/tutorial001_an_py39.py hl[14] *}

Utilizar `UploadFile` tem várias vantagens sobre `bytes`:

* Você não precisa utilizar o `File()` no valor padrão do parâmetro.

But there are several cases in which you might benefit from using `UploadFile`.

## File Parameters with `UploadFile`

Define a file parameter with a type of `UploadFile`:

//// tab | Python 3.9+

```Python hl_lines="14"
{!> ../../docs_src/request_files/tutorial001_an_py39.py!}
```

////

✔️ 🤯 👈 👉 ⛓ 👈 🎂 🎚 🔜 🏪 💾. 👉 🔜 👷 👍 🤪 📁.

✋️ 📤 📚 💼 ❔ 👆 💪 💰 ⚪️➡️ ⚙️ `UploadFile`.

## 📁 🔢 ⏮️ `UploadFile`

🔬 📁 🔢 ⏮️ 🆎 `UploadFile`:

```Python hl_lines="12"
{!../../docs_src/request_files/tutorial001.py!}
```

⚙️ `UploadFile` ✔️ 📚 📈 🤭 `bytes`:

* 👆 🚫 ✔️ ⚙️ `File()` 🔢 💲 🔢.
* ⚫️ ⚙️ "🧵" 📁:

Aber es gibt viele Fälle, in denen Sie davon profitieren, `UploadFile` zu verwenden.

## Datei-Parameter mit `UploadFile`

Definieren Sie einen Datei-Parameter mit dem Typ `UploadFile`:

//// tab | Python 3.9+

```Python hl_lines="14"
{!> ../../docs_src/request_files/tutorial001_an_py39.py!}
```

////

Mas existem vários casos em que você pode se beneficiar ao usar `UploadFile`.

## Parâmetros de arquivo com `UploadFile`

Defina um parâmetro de arquivo com o tipo `UploadFile`

//// tab | Python 3.9+

```Python hl_lines="14"
{!> ../../docs_src/request_files/tutorial001_an_py39.py!}
```

////

import warnings

import pytest
from fastapi import FastAPI, File, Form, UploadFile
from fastapi.dependencies.utils import (
    multipart_incorrect_install_error,
    multipart_not_installed_error,
)


def test_incorrect_multipart_installed_form(monkeypatch):
    monkeypatch.setattr("python_multipart.__version__", "0.0.12")
    with warnings.catch_warnings(record=True):
        warnings.simplefilter("always")

    # For coverage
    # TODO: in theory this would allow declaring types that could be lists of UploadFile
    # and other types, but I'm not even sure it's a good idea to support it as a first
    # class "feature"
    assert is_uploadfile_sequence_annotation(Union[List[str], List[UploadFile]])


def test_is_pv1_scalar_field():
    # For coverage
    class Model(BaseModel):

文件作为「表单数据」上传。

如果把*路径操作函数*参数的类型声明为 `bytes`，**FastAPI** 将以 `bytes` 形式读取和接收文件内容。

这种方式把文件的所有内容都存储在内存里，适用于小型文件。

不过，很多情况下，`UploadFile` 更好用。

## 含 `UploadFile` 的文件参数

定义文件参数时使用 `UploadFile`：

```Python hl_lines="12"
{!../../docs_src/request_files/tutorial001.py!}
```

`UploadFile` 与 `bytes` 相比有更多优势：

* 使用 `spooled` 文件：
    * 存储在内存的文件超出最大上限时，FastAPI 会把文件存入磁盘；
* 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；