Pero en este caso, la misma aplicación de **FastAPI** manejará la API y la autenticación.

Así que, revisémoslo desde ese punto de vista simplificado:

* El usuario escribe el `username` y `password` en el frontend, y presiona `Enter`.
* El frontend (ejecutándose en el navegador del usuario) envía ese `username` y `password` a una URL específica en nuestra API (declarada con `tokenUrl="token"`).

            * **FastAPI** adds a reference here to the global JSON Schemas in another place in your OpenAPI instead of including it directly. This way, other applications and clients can use those JSON Schemas directly, provide better code generation tools, etc.

///

The generated responses in the OpenAPI for this *path operation* will be:

```JSON hl_lines="3-12"
{
    "responses": {
        "404": {

These **"type hints"** or annotations are a special syntax that allow declaring the <abbr title="for example: str, int, float, bool">type</abbr> of a variable.

By declaring types for your variables, editors and tools can give you better support.

This is just a **quick tutorial / refresher** about Python type hints. It covers only the minimum necessary to use them with **FastAPI**... which is actually very little.

        .putShort((short) 0x0000)
        .putShort((short) 0x0000);
    assertEquals(hashCode, hasher.hash().asLong());
  }

  public void testHashFloatIsStable() {
    // Just a spot check.  Better than nothing.
    Hasher hasher = HASH_FN.newHasher();
    hasher.putFloat(0x01000101f).putFloat(0f);
    assertEquals(0x49f9d18ee8ae1b28L, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();

    assertThat(Resources.toByteArray(resource)).isEqualTo(I18N.getBytes(UTF_8));
  }

  public void testReadLines() throws IOException {
    // TODO(chrisn): Check in a better resource
    URL resource = getClass().getResource("testdata/i18n.txt");
    assertEquals(ImmutableList.of(I18N), Resources.readLines(resource, UTF_8));
  }

And these models are all sharing a lot of the data and duplicating attribute names and types.

We could do better.

We can declare a `UserBase` model that serves as a base for our other models. And then we can make subclasses of that model that inherit its attributes (type declarations, validation, etc).

Ici, avec `ge=1`, `item_id` devra être un nombre entier "`g`reater than or `e`qual" à `1`.

{* ../../docs_src/path_params_numeric_validations/tutorial004_an_py39.py hl[10] *}

## Validations numériques : supérieur ou égal et inférieur ou égal

La même chose s'applique pour :

* `gt` : `g`reater `t`han
* `le` : `l`ess than or `e`qual

Aqui, com `ge=1`, `item_id` precisará ser um número inteiro “`g`reater than or `e`qual” a `1`.

{* ../../docs_src/path_params_numeric_validations/tutorial004_an_py39.py hl[10] *}

## Validações numéricas: maior que e menor que ou igual { #number-validations-greater-than-and-less-than-or-equal }

O mesmo se aplica a:

* `gt`: maior que (`g`reater `t`han)
* `le`: menor que ou igual (`l`ess than or `e`qual)

      afe.initCause(ie);
      throw afe;
    }
  }

  /**
   * Spin-waits up to the specified number of milliseconds for the given thread to enter a wait
   * state: BLOCKED, WAITING, or TIMED_WAITING.
   */
  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  void waitForThreadToEnterWaitState(Thread thread, long timeoutMillis) {

    return !disjoint(a, b);
  }

  private static Method extractMethod(Test test) {
    if (test instanceof AbstractTester) {
      AbstractTester<?> tester = (AbstractTester<?>) test;
      return getMethod(tester.getClass(), tester.getTestMethodName());
    } else if (test instanceof TestCase) {
      TestCase testCase = (TestCase) test;
      return getMethod(testCase.getClass(), testCase.getName());