## Importer `Query`

Pour cela, importez d'abord `Query` depuis `fastapi` :

```Python hl_lines="3"
{!../../../docs_src/query_params_str_validations/tutorial002.py!}
```

## Utiliser `Query` comme valeur par défaut

Construisez ensuite la valeur par défaut de votre paramètre avec `Query`, en choisissant 50 comme `max_length` :

```Python hl_lines="9"

	cases := []struct {
		startIndex int
		endIndex   int
		expected   bool
	}{
		{startIndex: 0, endIndex: 10, expected: false},
		{startIndex: 5, endIndex: 20, expected: false},
		{startIndex: 50, endIndex: 50, expected: true},
	}

	for _, c := range cases {
		wcib := &watchCacheIntervalBuffer{
			startIndex: c.startIndex,
			endIndex:   c.endIndex,
		}
		actual := wcib.isEmpty()

    `Union[str, None]` hingegen erlaubt ihren Editor, Sie besser zu unterstützen und Fehler zu erkennen.

## Zusätzliche Validierung

Wir werden bewirken, dass, obwohl `q` optional ist, wenn es gegeben ist, **seine Länge 50 Zeichen nicht überschreitet**.

### `Query` und `Annotated` importieren

Importieren Sie zuerst:

* `Query` von `fastapi`
* `Annotated` von `typing` (oder von `typing_extensions` in Python unter 3.9)

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000003b0  73 ea fe 13 e2 61 c1 38  05 16 03 03 00 4a 82 ab  |s....a.8.....J..|
000003c0  72 1f 06 41 41 a7 4e 41  ab ae 2b b4 af 45 a9 11  |r..AA.NA..+..E..|

00000180  e5 96 d9 74 7b f3 58 9f  6c 61 3c c0 b0 41 d4 d9  |...t{.X.la<..A..|
00000190  2b 2b 24 23 77 5b 1c 3b  bd 75 5d ce 20 54 cf a1  |++$#w[.;.u]. T..|
000001a0  63 87 1d 1e 24 c4 f3 1d  1a 50 8b aa b6 14 43 ed  |c...$....P....C.|
000001b0  97 a7 75 62 f4 14 c8 52  d7 02 03 01 00 01 a3 46  |..ub...R.......F|
000001c0  30 44 30 0e 06 03 55 1d  0f 01 01 ff 04 04 03 02  |0D0...U.........|

                new Facet(FacetType.fixed, "jst.web", null),
                new Facet(FacetType.installed, "jst.web", "2.4"),
                new Facet(FacetType.installed, "jst.java", "5.0")])
    }

    def applyFirstToWarProject_shouldHaveWebProjectAndClasspathTask() {
        when:
        project.apply(plugin: 'eclipse-wtp')
        project.apply(plugin: 'war')

     *
     * @since 5.0
     */
    @Input
    public String getProjectName() {
        return projectName == null ? projectDir.getAsFile().getName() : projectName;
    }

    /**
     * The name of the package to use for generated source.
     *
     * This property can be set via command-line option '--package'.
     *
     * @since 5.0
     */
    @Input

          <div class="flex items-center">
            <div>
              <img class="inline-block h-9 w-9 rounded-full bg-blue-50" src="/static/img/izzy.png" alt="">
            </div>
            <div class="ml-4">
              <p class="text-base font-medium text-gray-50">{{ user }}</p>
              <a href="logout" class="text-xs font-medium text-gray-400 hover:text-gray-300">Sign out</a>
            </div>
          </div>

        mavenRepo.module("foo", "bar", "1.0").publish()
        mavenRepo.module("foo", "bar", "2.0").publish()
        mavenRepo.module("foo", "bar", "3.0").dependsOn('foo', 'baz', '5.0').publish()


        mavenRepo.module("foo", "baz", "5.0").publish()

        createDirs("a", "b", "c", "d", "e")
        file("settings.gradle") << """include 'a', 'b', 'c', 'd', 'e'
rootProject.name = 'root'
"""

UserRegionBegin dt=11 task=8 name_string=29 stack=49
HeapAlloc dt=7 heapalloc_value=1761280
HeapAlloc dt=18 heapalloc_value=1769472
GoCreate dt=52 new_g=49 new_stack=17 stack=50
GoCreate dt=12 new_g=50 new_stack=17 stack=50
HeapAlloc dt=11 heapalloc_value=1777664
GoCreate dt=9 new_g=51 new_stack=17 stack=50
UserRegionEnd dt=9 task=8 name_string=29 stack=51
GoBlock dt=11 reason_string=19 stack=52
HeapAlloc dt=12 heapalloc_value=1785856