## docstringを用いた説明

説明文は長くて複数行におよぶ傾向があるので、関数<abbr title="ドキュメントに使用される関数内の最初の式（変数に代入されていない）としての複数行の文字列">docstring</abbr>内に*path operation*の説明文を宣言できます。すると、**FastAPI** は説明文を読み込んでくれます。

docstringに<a href="https://en.wikipedia.org/wiki/Markdown" class="external-link" target="_blank">Markdown</a>を記述すれば、正しく解釈されて表示されます。（docstringのインデントを考慮して）

```Python hl_lines="19-27"
{!../../docs_src/path_operation_configuration/tutorial004.py!}
```

これは対話的ドキュメントで使用されます:

 * [OkLog](https://github.com/simonpercic/OkLog): Response logging interceptor for OkHttp. Logs a URL link with URL-encoded response for every OkHttp call.
 * [Okurl](https://github.com/yschimke/okurl/wiki) A curl-like client for social networks and other APIs.
 * [PersistentCookieJar](https://github.com/franmontiel/PersistentCookieJar): A persistent `CookieJar`.

/**
 * A queue which forwards all its method calls to another queue. Subclasses should override one or
 * more methods to modify the behavior of the backing queue as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingQueue} forward <b>indiscriminately</b> to the

 * be used, at a small efficiency penalty, to enforce the distinction in the type system.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/PrimitivesExplained#unsigned-support">unsigned
 * primitive utilities</a>.
 *
 * @author Louis Wasserman
 * @author Brian Milch
 * @author Colin Evans
 * @since 10.0
 */
@GwtCompatible

/**
 * A queue which forwards all its method calls to another queue. Subclasses should override one or
 * more methods to modify the behavior of the backing queue as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingQueue} forward <b>indiscriminately</b> to the

/**
 * A set which forwards all its method calls to another set. Subclasses should override one or more
 * methods to modify the behavior of the backing set as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSet} forward <b>indiscriminately</b> to the

 *
 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/StringsExplained#charsets">{@code Charsets}</a>.
 *
 * @author Mike Bostock
 * @since 1.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Charsets {
  private Charsets() {}

```

## 文档字符串（`docstring`）

描述内容比较长且占用多行时，可以在函数的 <abbr title="函数中作为第一个表达式，用于文档目的的一个多行字符串（并没有被分配个任何变量）">docstring</abbr> 中声明*路径操作*的描述，**FastAPI** 支持从文档字符串中读取描述内容。

文档字符串支持 <a href="https://en.wikipedia.org/wiki/Markdown" class="external-link" target="_blank">Markdown</a>，能正确解析和显示 Markdown 的内容，但要注意文档字符串的缩进。

```Python hl_lines="19-27"
{!../../docs_src/path_operation_configuration/tutorial004.py!}
```

for it.

If the feature has merit, it will go through a thorough process of API design
and review. Any code should come after this.

[APIs]: https://en.wikipedia.org/wiki/Application_programming_interface
[issue]: https://github.com/google/guava/issues

Pull requests
-------------

Unless the change is a trivial fix such as for a typo, it's generally best to

 * Subclasses should override one or more methods to modify the behavior of the backing deque as
 * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingBlockingDeque} forward <b>indiscriminately</b>