## Ringkasan, secara bertahap

### Langkah 1: impor `FastAPI`

{* ../../docs_src/first_steps/tutorial001.py hl[1] *}

`FastAPI` adalah class Python yang menyediakan semua fungsionalitas API anda.

/// note | Detail Teknis

`FastAPI` adalah class turunan langsung dari `Starlette`.

Anda bisa menggunakan semua fungsionalitas <a href="https://www.starlette.io/" class="external-link" target="_blank">Starlette</a> dengan `FastAPI` juga.

            context = new EncryptionNegotiateContext(mockConfig, null);

            assertNull(context.getCiphers());
            assertEquals(4, context.size()); // Size returns 4 as base (implementation detail)
        }

        @ParameterizedTest
        @DisplayName("Should encode with different cipher counts")
        @ValueSource(ints = { 0, 1, 2, 5, 10 })
        void testEncodeWithDifferentCipherCounts(int count) {

 [bom]: https://docs.gradle.org/6.2/userguide/platforms.html#sub:bom_import
 [bouncy_castle_releases]: https://www.bouncycastle.org/releasenotes.html
 [CVE-2021-0341]: https://nvd.nist.gov/vuln/detail/CVE-2021-0341
 [CVE-2022-24329]: https://nvd.nist.gov/vuln/detail/CVE-2022-24329
 [dev_server]: https://github.com/square/okhttp/blob/482f88300f78c3419b04379fc26c3683c10d6a9d/samples/guide/src/main/java/okhttp3/recipes/kt/DevServer.kt

import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import java.util.NoSuchElementException;
import org.jspecify.annotations.Nullable;

/**
 * Implementation detail for the internal structure of {@link Range} instances. Represents a unique
 * way of "cutting" a "number line" (actually of instances of type {@code C}, not necessarily

Eğer tarayıcınızda <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a> sayfasını açarsanız, şuna benzer güzel bir HTTP hatası ile karşılaşırsınız:

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }

Якщо ж відкрити у браузері посилання <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, то побачимо цікаву HTTP-помилку:

```JSON
{
  "detail": [
    {
      "type": "int_parsing",
      "loc": [
        "path",
        "item_id"
      ],
      "msg": "Input should be a valid integer, unable to parse string as an integer",
      "input": "foo"
    }

ここで、クエリパラメータ `needy` は `str` 型の必須のクエリパラメータです

以下のURLをブラウザで開くと:

```
http://127.0.0.1:8000/items/foo-item
```

...必須のパラメータ `needy` を加えなかったので、以下の様なエラーが表示されます:

```JSON
{
    "detail": [
        {
            "loc": [
                "query",
                "needy"
            ],
            "msg": "field required",
            "type": "value_error.missing"
        }
    ]
}

            [*] https://code.google.com/p/google-web-toolkit/wiki/ResourceOracle#When_multiple_PathPrefix_es_have_the_same_path
                https://code.google.com/p/google-web-toolkit/issues/detail?id=7581
            -->
          <execution>
            <id>gwt-test</id>
            <goals>
              <goal>test</goal>
            </goals>
            <configuration>

///

## Validation de données

Si vous allez sur <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, vous aurez une belle erreur HTTP :

```JSON
{
    "detail": [
        {
            "loc": [
                "path",
                "item_id"
            ],
            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]

{!../../docs_src/bigger_applications/app/main.py!}
```

and it will work correctly, together with all the other *path operations* added with `app.include_router()`.

/// info | Very Technical Details

**Note**: this is a very technical detail that you probably can **just skip**.

---

The `APIRouter`s are not "mounted", they are not isolated from the rest of the application.