constraints.ParametersScriptAssert.message = The script expression "{script}" is not true.
constraints.Range.message = {item} must be between {min} and {max}.
constraints.SafeHtml.message = {item} contains unsafe HTML content.
constraints.ScriptAssert.message = The script expression "{script}" is not true.
constraints.URL.message = {item} is not a valid URL.
constraints.Required.message = {item} is required.

constraints.ParametersScriptAssert.message = The script expression "{script}" is not true.
constraints.Range.message = {item} must be between {min} and {max}.
constraints.SafeHtml.message = {item} contains unsafe HTML content.
constraints.ScriptAssert.message = The script expression "{script}" is not true.
constraints.URL.message = {item} is not a valid URL.
constraints.Required.message = {item} is required.

## `Union` 또는 `anyOf`

두 가지 이상의 타입을 포함하는 `Union`으로 응답을 선언할 수 있습니다. 이는 응답이 그 중 하나의 타입일 수 있음을 의미합니다.

OpenAPI에서는 이를 `anyOf`로 정의합니다.

이를 위해 표준 Python 타입 힌트인 <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>을 사용할 수 있습니다:

/// note | 참고

 *
 * <p>A {@code UnicodeEscaper} instance is required to be stateless, and safe when used concurrently
 * by multiple threads.
 *
 * <p>Popular escapers are defined as constants in classes like {@link
 * com.google.common.html.HtmlEscapers} and {@link com.google.common.xml.XmlEscapers}. To create
 * your own escapers extend this class and implement the {@link #escape(int)} method.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible

 *
 * <p>A {@code UnicodeEscaper} instance is required to be stateless, and safe when used concurrently
 * by multiple threads.
 *
 * <p>Popular escapers are defined as constants in classes like {@link
 * com.google.common.html.HtmlEscapers} and {@link com.google.common.xml.XmlEscapers}. To create
 * your own escapers extend this class and implement the {@link #escape(int)} method.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible

 * commandline with the <code>-Dproperty.name=value</code> VM parameter
 * will override properties from the configuration file.
 * <p>
 * There are several ways to set jCIFS properties. See
 * the <a href="../overview-summary.html#scp">overview page of the API
 * documentation</a> for details.
 */

public class Config {

    /**
     * Counter for tracking socket connections.
     */
    public static int socketCount = 0;

   *
   * <p>If you are designing a new system that needs HMAC, prefer {@link #hmacSha256} or other
   * future-proof algorithms <a
   * href="https://datatracker.ietf.org/doc/html/rfc6151#section-2.3">over {@code hmacMd5}</a>.
   *
   * @param key the secret key
   * @throws IllegalArgumentException if the given key is inappropriate for initializing this MAC
   * @since 20.0
   */

   * {@link java.io.PrintWriter#format PrintWriter.format}, and related methods. These support the
   * full range of <a
   * href="https://docs.oracle.com/javase/9/docs/api/java/util/Formatter.html#syntax">format
   * specifiers</a>, and alert you to usage errors by throwing {@link
   * java.util.IllegalFormatException}.
   *

{* ../../docs_src/query_params_str_validations/tutorial006.py hl[7] *}

/// info | 정보

이전에 `...`를 본적이 없다면: 특별한 단일값으로, <a href="https://docs.python.org/3/library/constants.html#Ellipsis" class="external-link" target="_blank">파이썬의 일부이며 "Ellipsis"라 부릅니다</a>.

///

이렇게 하면 **FastAPI**가 이 매개변수는 필수임을 알 수 있습니다.

## 쿼리 매개변수 리스트 / 다중값

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

第二個參數是 <a href="https://docs.python.org/zh-tw/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> 的預設回傳值。

如果沒有提供，預設值為 `None`，這裡我們提供 `"World"` 作為預設值。

///

然後你可以呼叫這個 Python 程式：

//// tab | Linux, macOS, Windows Bash

<div class="termy">