## 선택적 매개변수

같은 방법으로 기본값을 `None`으로 설정하여 선택적 매개변수를 선언할 수 있습니다:

```Python hl_lines="9"
{!../../docs_src/query_params/tutorial002.py!}
```

이 경우 함수 매개변수 `q`는 선택적이며 기본값으로 `None` 값이 됩니다.

/// check | "확인"

**FastAPI**는 `item_id`가 경로 매개변수이고 `q`는 경로 매개변수가 아닌 쿼리 매개변수라는 것을 알 정도로 충분히 똑똑합니다.

///

/// note | "참고"

FastAPI는 `q`가 `= None`이므로 선택적이라는 것을 인지합니다.

  // matches.  A request that specifies a target namespace matches
  // only if either (a) this list contains that target namespace or
  // (b) this list contains "*".  Note that "*" matches any
  // specified namespace but does not match a request that _does
  // not specify_ a namespace (see the `clusterScope` field for
  // that).
  // This list may be empty, but only if `clusterScope` is true.
  // +optional
  // +listType=set

/// tip | "Tipp"

Bevorzugen Sie die `Annotated`-Version, falls möglich.

///

```Python hl_lines="7  48  55-56  59-60  69-75"
{!> ../../docs_src/security/tutorial004.py!}
```

////

/// note | "Hinweis"

Wenn Sie sich die neue (gefakte) Datenbank `fake_users_db` anschauen, sehen Sie, wie das gehashte Passwort jetzt aussieht: `"$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW"`.

///

import org.apache.maven.plugin.version.PluginVersionResolutionException;
import org.apache.maven.project.MavenProject;

/**
 * A facade that provides lifecycle services to components outside maven core.
 * <p>
 * Note that this component is not normally used from within core itself.
 *
 */
@Named
@Singleton
public class DefaultLifecycleExecutor implements LifecycleExecutor {

    private final LifeCyclePluginAnalyzer lifeCyclePluginAnalyzer;

`Path`, `Query` 그리고 `Cookie`를 사용한 동일한 구조를 이용하여 헤더 매개변수를 선언합니다.

첫 번째 값은 기본값이며, 추가 검증이나 어노테이션 매개변수 모두 전달할 수 있습니다:

```Python hl_lines="9"
{!../../docs_src/header_params/tutorial001.py!}
```

/// note | "기술 세부사항"

`Header`는 `Path`, `Query` 및 `Cookie`의 "자매"클래스입니다. 이 역시 동일한 공통 `Param` 클래스를 상속합니다.

`Query`, `Path`, `Header` 그리고 다른 것들을 `fastapi`에서 임포트 할 때, 이들은 실제로 특별한 클래스를 반환하는 함수임을 기억하세요.

///

/// info | "정보"

  }

  @GwtIncompatible // String.toUpperCase() has browser semantics
  public void testEqualsIgnoreCaseUnicodeEquivalence() {
    // Note that it's possible in future that the JDK's idea to toUpperCase() or equalsIgnoreCase()
    // may change and break assumptions in this test [*]. This is not a bug in the implementation of
    // Ascii.equalsIgnoreCase(), but it is a signal that its documentation may need updating as
    // regards edge cases.

COPY devel.packages.txt /devel.packages.txt
COPY cuda.packages.txt /cuda.packages.txt
RUN /setup.sources.sh && /setup.packages.sh /devel.packages.txt

# Install various tools.
# - bats: bash unit testing framework
#         NOTE: v1.6.0 seems to have a bug that made "git" in setup_file break
# - bazelisk: always use the correct bazel version
# - buildifier: clean bazel build deps
# - buildozer: clean bazel build deps

 * Invokable<List<String>, ?> invokable = new TypeToken<List<String>>() {}.method(getMethod);
 * assertEquals(TypeToken.of(String.class), invokable.getReturnType()); // Not Object.class!
 * assertEquals(new TypeToken<List<String>>() {}, invokable.getOwnerType());
 * }</pre>
 *
 * <p><b>Note:</b> earlier versions of this class inherited from {@link
 * java.lang.reflect.AccessibleObject AccessibleObject} and {@link

 * All components may use this storage to associate arbitrary data with a session.
 * <p>
 * Unlike a cache, this session data is not subject to purging. For this same reason, session data should also not be
 * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion.
 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *
 * @see Session#getData()
 * @since 4.0.0
 */
@Experimental

upgrades in a lower environment (DEV, QA, UAT) before applying to production. Performing blind upgrades in production environments carries significant risk. - Read the release notes for MinIO *before* performing any upgrade, there is no forced requirement to upgrade to latest release upon every release. Some release may not be relevant to your setup, avoid upgrading production environments unnecessarily. - If you plan to use `mc admin update`, MinIO process must have write access to the parent directory...