만약 언더스코어를 하이픈으로 자동 변환을 비활성화해야 할 어떤 이유가 있다면, `Header`의 `convert_underscores` 매개변수를 `False`로 설정하십시오:

{* ../../docs_src/header_params/tutorial002.py hl[10] *}

/// warning | 경고

`convert_underscore`를 `False`로 설정하기 전에, 어떤 HTTP 프록시들과 서버들은 언더스코어가 포함된 헤더 사용을 허락하지 않는다는 것을 명심하십시오.

///

## 중복 헤더

중복 헤더들을 수신할 수 있습니다. 즉, 다중값을 갖는 동일한 헤더를 뜻합니다.

타입 정의에서 리스트를 사용하여 이러한 케이스를 정의할 수 있습니다.

    private SetView() {} // no subclasses but our own

    /**
     * Returns an immutable copy of the current contents of this set view. Does not support null
     * elements.
     *
     * <p><b>Warning:</b> this may have unexpected results if a backing set of this view uses a
     * nonstandard notion of equivalence, for example if it is a {@link TreeSet} using a comparator

                buff.a("Message styles: ");
                buff.trace("trace").a(' ');
                buff.debug("debug").a(' ');
                buff.info("info").a(' ');
                buff.warning("warning").a(' ');
                buff.error("error").a(' ');
                buff.success("success").a(' ');
                buff.failure("failure").a(' ');
                buff.strong("strong").a(' ');

如果你引发任何异常，它将传递给使用 `yield` 的依赖项，包括 `HTTPException`。在大多数情况下你应当从使用 `yield` 的依赖项中重新抛出捕获的异常或者一个新的异常来确保它会被正确的处理。

///

## 包含 `yield`, `HTTPException`, `except` 的依赖项和后台任务

/// warning | 注意

你大概率不需要了解这些技术细节，可以跳过这一章节继续阅读后续的内容。

如果你使用的FastAPI的版本早于0.106.0，并且在使用后台任务中使用了包含 `yield` 的依赖项中的资源，那么这些细节会对你有一些用处。

///

### 包含 `yield` 和 `except` 的依赖项的技术细节

            if (!Arrays.asList("warn", "warning", "error").contains(c)) {
                context.parsingFailed = true;
                context.parserRequest
                        .logger()
                        .error("Invalid fail on severity threshold '" + c
                                + "'. Supported values are 'WARN', 'WARNING' and 'ERROR'.");
            }
        });

   * simply use the standard method-chaining idiom, as illustrated in the documentation at top,
   * configuring a {@code CacheBuilder} and building your {@link Cache} all in a single statement.
   *
   * <p><b>Warning:</b> if you ignore the above advice, and use this {@code CacheBuilder} to build a
   * cache whose key or value type is incompatible with the weigher, you will likely experience a

O mesmo exemplo de antes, retornando uma `HTMLResponse`, poderia parecer com:

{* ../../docs_src/custom_response/tutorial003_py39.py hl[2,7,19] *}

/// warning | Atenção

Uma `Response` retornada diretamente em sua *função de operação de rota* não será documentada no OpenAPI (por exemplo, o `Content-Type` não será documentado) e não será visível na documentação interativa automática.

The same example from above, returning an `HTMLResponse`, could look like:

{* ../../docs_src/custom_response/tutorial003_py39.py hl[2,7,19] *}

/// warning

A `Response` returned directly by your *path operation function* won't be documented in OpenAPI (for example, the `Content-Type` won't be documented) and won't be visible in the automatic interactive docs.

///

/// info

Das gleiche Beispiel von oben, das eine `HTMLResponse` zurückgibt, könnte so aussehen:

{* ../../docs_src/custom_response/tutorial003_py39.py hl[2,7,19] *}

/// warning | Achtung

 * override one or more methods to modify the behavior of the backing map as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingNavigableMap} forward <i>indiscriminately</i>
 * to the methods of the delegate. For example, overriding {@link #put} alone <i>will not</i> change