}
  }

  private void expectReturnsTrue(Target target) {
    String message = Platform.format("retainAll(%s) should return true", target);
    assertTrue(message, collection.retainAll(target.toRetain));
  }

  private void expectReturnsFalse(Target target) {
    String message = Platform.format("retainAll(%s) should return false", target);
    assertFalse(message, collection.retainAll(target.toRetain));
  }

# 请求表单与文件

FastAPI 支持同时使用 `File` 和 `Form` 定义文件和表单字段。

!!! info "说明"

    接收上传文件或表单数据，要预先安装 <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>。

    例如，`pip install python-multipart`。

## 导入 `File` 与 `Form`

```Python hl_lines="1"
{!../../../docs_src/request_forms_and_files/tutorial001.py!}
```

## 定义 `File` 与 `Form` 参数

创建文件和表单参数的方式与 `Body` 和 `Query` 一样：

    ```

=== "Python 3.6+"

    ```Python hl_lines="1"
    {!> ../../../docs_src/request_forms_and_files/tutorial001_an.py!}
    ```

=== "Python 3.6+ без Annotated"

    !!! tip "Подсказка"
        Предпочтительнее использовать версию с аннотацией, если это возможно.

    ```Python hl_lines="1"
    {!> ../../../docs_src/request_forms_and_files/tutorial001.py!}
    ```

		Description:    "Error parsing the X-Amz-Credential parameter; the Credential is mal-formed; expecting \"<YOUR-AKID>/YYYYMMDD/REGION/SERVICE/aws4_request\".",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedDate: {
		Code:           "MalformedDate",
		Description:    "Invalid date format header, expected to be in ISO8601, RFC1123 or RFC1123Z time format.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedPresignedDate: {

    ```

The files and form fields will be uploaded as form data and you will receive the files and form fields.

And you can declare some of the files as `bytes` and some as `UploadFile`.

!!! warning

			if err := tr.handleSparseFile(hdr, rawHdr); err != nil {
				return nil, err
			}

			// Set the final guess at the format.
			if format.has(FormatUSTAR) && format.has(FormatPAX) {
				format.mayOnlyBe(FormatUSTAR)
			}
			hdr.Format = format
			return hdr, nil // This is a file, so stop
		}
	}
}

// handleRegularFile sets up the current file reader and padding such that it

Klaus Post <******@****.***> 1709920248 +0100

// AWS S3 compatible.
//
// Therefore, Format returns the last 16 bytes of an encrypted
// ETag.
//
// In general, a caller has to distinguish the following cases:
//   - The object is a multipart object. In this case,
//     Format returns the ETag unmodified.
//   - The object is a SSE-KMS or SSE-C encrypted single-
//     part object. In this case, Format returns the last

Klaus Post <******@****.***> 1713545023 -0700

	ErrMalformedBucketObjectConfig = errors.New("invalid bucket object lock config")
	// ErrInvalidRetentionDate - indicates that retention date needs to be in ISO 8601 format
	ErrInvalidRetentionDate = errors.New("date must be provided in ISO 8601 format")
	// ErrPastObjectLockRetainDate - indicates that retention date must be in the future
	ErrPastObjectLockRetainDate = errors.New("the retain until date must be in the future")