Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

/// note

This is supported since FastAPI version `0.113.0`. 🤓

///

## Pydantic Models for Forms

   * value} before proceeding with the {@link #put} operation. If the bimap previously contained the
   * provided key-value mapping, this method has no effect.
   *
   * <p>Note that a successful call to this method could cause the size of the bimap to increase by
   * one, stay the same, or even decrease by one.
   *

 */
@Experimental
public interface DependencyResolver extends Service {

    /**
     * Collects the transitive dependencies of some artifacts and builds a dependency graph for the given path scope.
     * Note that this operation is only concerned about determining the coordinates of the transitive dependencies and
     * does not actually resolve the artifact files.
     *
     * @param session the {@link Session}, must not be {@code null}

    @Override
    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
        logMessage(
                Diagnostic.Kind.NOTE, "Processing " + roundEnv.getRootElements().size() + " classes");

        for (Element element : roundEnv.getElementsAnnotatedWith(Named.class)) {
            if (element instanceof TypeElement typeElement) {

 *          deduced from the Mojo's implementation language, but can be specified to allow a custom
 *          ComponentConfigurator implementation to be used.
 *          <br>
 *          <i>NOTE: This will only be used in very special cases, using a highly controlled vocabulary of possible
 *          values. (Elements like this are why it's a good idea to use the descriptor tools.)</i>
 *      </td>
 *   </tr>
 *   <tr>

///

它可以：

* 在响应中返回状态码
* 在 OpenAPI 概图（及用户界面）中存档：

<img src="/img/tutorial/response-status-code/image01.png">

/// note | "笔记"

某些响应状态码表示响应没有响应体（参阅下一章）。

FastAPI 可以进行识别，并生成表明无响应体的 OpenAPI 文档。

///

## 关于 HTTP 状态码

/// note | "笔记"

如果已经了解 HTTP 状态码，请跳到下一章。

///

在 HTTP 协议中，发送 3 位数的数字状态码是响应的一部分。

这些状态码都具有便于识别的关联名称，但是重要的还是数字。

简言之：

   *   <li>{@code false} in all other situations.
   * </ul>
   *
   * <p>This assumes that any non-null objects passed to this function conform to the {@code
   * equals()} contract.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated; use {@link
   * java.util.Objects#equals} instead.
   */
  public static boolean equal(@CheckForNull Object a, @CheckForNull Object b) {

     * <p>
     * Note: only one, this method or {@link #getRecommendedVersion()} method must return non-{@code null} value.
     */
    @Nullable
    VersionRange getVersionRange();

    /**
     * Returns the recommended version of this constraint, or {@code null} if none.
     * <p>

<img src="/img/tutorial/response-status-code/image01.png">

/// note | "Nota"

Alguns códigos de resposta (consulte a próxima seção) indicam que a resposta não possui um corpo.

O FastAPI sabe disso e produzirá documentos OpenAPI informando que não há corpo de resposta.

///

## Sobre os códigos de status HTTP

/// note | "Nota"

Se você já sabe o que são códigos de status HTTP, pule para a próxima seção.

```Python
contents = await myfile.read()
```

在普通 `def` *路径操作函数*  内，则可以直接访问 `UploadFile.file`，例如：

```Python
contents = myfile.file.read()
```

/// note | "`async` 技术细节"

使用 `async` 方法时，**FastAPI** 在线程池中执行文件方法，并 `await` 操作完成。

///

/// note | "Starlette 技术细节"

**FastAPI** 的 `UploadFile` 直接继承自 **Starlette** 的 `UploadFile`，但添加了一些必要功能，使之与 **Pydantic** 及 FastAPI 的其它部件兼容。

///

## 什么是 「表单数据」