## 메타데이터 선언

`Query`에 동일한 매개변수를 선언할 수 있습니다.

예를 들어, `title` 메타데이터 값을 경로 매개변수 `item_id`에 선언하려면 다음과 같이 입력할 수 있습니다:

{* ../../docs_src/path_params_numeric_validations/tutorial001.py hl[10] *}

/// note | 참고

경로 매개변수는 경로의 일부여야 하므로 언제나 필수적입니다.

즉, `...`로 선언해서 필수임을 나타내는게 좋습니다.

그럼에도 `None`으로 선언하거나 기본값을 지정할지라도 아무 영향을 끼치지 않으며 언제나 필수입니다.

///

## 필요한 경우 매개변수 정렬하기

 * {@link ConcurrentHashMap}. It supports all optional operations of the {@code ConcurrentMap}
 * interface. It does not permit null keys or values.
 *
 * <p><b>Note:</b> by default, the returned map uses equality comparisons (the {@link Object#equals
 * equals} method) to determine equality for keys or values. However, if {@link #weakKeys} was

It doesn't return a large `str` containing the data in JSON format (as a string). It returns a Python standard data structure (e.g. a `dict`) with values and sub-values that are all compatible with JSON.

/// note

`jsonable_encoder` is actually used by **FastAPI** internally to convert data. But it is useful in many other scenarios.

👆 💪 🚮 🎚 🕐❔ 👆 📨 `Response` 🔗.

✍ 📨 🔬 [📨 📨 🔗](response-directly.md){.internal-link target=_blank} & 🚶‍♀️ 🎚 🌖 🔢:

{* ../../docs_src/response_headers/tutorial001.py hl[10:12] *}

/// note | 📡 ℹ

👆 💪 ⚙️ `from starlette.responses import Response` ⚖️ `from starlette.responses import JSONResponse`.

**FastAPI** 🚚 🎏 `starlette.responses` `fastapi.responses` 🏪 👆, 👩‍💻. ✋️ 🌅 💪 📨 👟 🔗 ⚪️➡️ 💃.

A função não retorna um grande `str` contendo os dados no formato JSON (como uma string). Mas sim, retorna uma estrutura de dados padrão do Python (por exemplo, um `dict`) com valores e subvalores compatíveis com JSON.

/// note | Nota

`jsonable_encoder` é realmente usado pelo **FastAPI** internamente para converter dados. Mas também é útil em muitos outros cenários.

Isso vai lhe permitir **reusar o modelo** em **múltiplos lugares** e também declarar validações e metadadados para todos os parâmetros de uma vez. 😎

/// note | Nota

Isso é possível desde a versão `0.115.0` do FastAPI. 🤓

///

## Parâmetros do Cabeçalho com um Modelo Pydantic

   * response body is [closed][ResponseBody]. The recipient of the callback may consume the response
   * body on another thread.
   *
   * Note that transport-layer success (receiving a HTTP response code, headers and body) does not
   * necessarily indicate application-layer success: `response` may still indicate an unhappy HTTP
   * response code like 404 or 500.
   */

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with LargeTest.
 *
 * <p>For more discussion, see {@linkplain com.google.common.base.AndroidIncompatible the
 * documentation on another copy of this annotation}.
 */

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with LargeTest.
 *
 * <p>For more discussion, see {@linkplain com.google.common.base.AndroidIncompatible the
 * documentation on another copy of this annotation}.
 */

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with LargeTest.
 *
 * <p>For more discussion, see {@linkplain com.google.common.base.AndroidIncompatible the
 * documentation on another copy of this annotation}.
 */