Starlette (and **FastAPI**) are based on <a href="https://anyio.readthedocs.io/en/stable/" class="external-link" target="_blank">AnyIO</a>, which makes it compatible with both Python's standard library <a href="https://docs.python.org/3/library/asyncio-task.html" class="external-link" target="_blank">asyncio</a> and <a href="https://trio.readthedocs.io/en/stable/" class="external-link" target="_blank">Trio</a>.

   * Returns a Writer that sends all output to the given {@link Appendable} target. Closing the
   * writer will close the target if it is {@link Closeable}, and flushing the writer will flush the
   * target if it is {@link java.io.Flushable}.
   *
   * @param target the object to which output will be sent
   * @return a new Writer object, unless target is a Writer, in which case the target is returned
   */

В этом случае они будут применяться ко всем *операциям пути* в приложении:

{* ../../docs_src/dependencies/tutorial012_an_py39.py hl[17] *}

So, a `datetime` object would have to be converted to a `str` containing the data in <a href="https://en.wikipedia.org/wiki/ISO_8601" class="external-link" target="_blank">ISO format</a>.

The same way, this database wouldn't receive a Pydantic model (an object with attributes), only a `dict`.

You can use `jsonable_encoder` for that.

  abstract ImmutableCollection<E> delegateCollection();

  @Override
  public boolean contains(@Nullable Object target) {
    // The collection's contains() is at least as fast as ImmutableList's
    // and is often faster.
    return delegateCollection().contains(target);
  }

  @Override
  public int size() {
    return delegateCollection().size();
  }

  @Override
  public boolean isEmpty() {

Here we'll see an example using <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a>.

**SQLModel** is built on top of <a href="https://www.sqlalchemy.org/" class="external-link" target="_blank">SQLAlchemy</a> and Pydantic. It was made by the same author of **FastAPI** to be the perfect match for FastAPI applications that need to use **SQL databases**.

Hier werden wir ein Beispiel mit <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a> sehen.

> 这个项目有怎样的历史？好像它只用了几周就从默默无闻变得众所周知……

在此，我们简单回顾一下 **FastAPI** 的历史。

## 备选方案

有那么几年，我曾领导数个开发团队为诸多复杂需求创建各种 API，这些需求包括机器学习、分布系统、异步任务、NoSQL 数据库等领域。

作为工作的一部分，我需要调研很多备选方案、还要测试并且使用这些备选方案。

**FastAPI** 其实只是延续了这些前辈的历史。

正如[备选方案](alternatives.md){.internal-link target=_blank}一章所述：

<blockquote markdown="1">

adicionados <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando o prefixo `X-`</a>.

Porém, se voce tiver cabeçalhos personalizados que deseja que um cliente no navegador possa ver, você precisa adicioná-los às suas configurações de CORS (saiba mais em [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), usando o parâmetro `expose_headers` descrito na <a href="https://www.starlette.dev/middle...

所以 OpenAPI为了相似的目的定义了自己的 <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.3.md#fixed-fields-20" class="external-link" target="_blank">`example`</a> (使用 `example`, 而不是 `examples`), 这也是文档 UI 所使用的 (使用 Swagger UI).