...makes the parameter optional, with a default value of `None`, the same as:


```Python
q: str | None = None
```

But the `Query` version declares it explicitly as being a query parameter.

Then, we can pass more parameters to `Query`. In this case, the `max_length` parameter that applies to strings:

```Python
q: str | None = Query(default=None, max_length=50)
```

## Return a `Response` directly { #return-a-response-directly }

You can also add headers when you return a `Response` directly.

Create a response as described in [Return a Response Directly](response-directly.md) and pass the headers as an additional parameter:

{* ../../docs_src/response_headers/tutorial001_py310.py hl[10:12] *}

/// note | Technical Details

* **No documentation**: Why document your API when an LLM can figure it out? Auto-generated OpenAPI docs are *so* 2020.
* **No serialization**: Just pass the raw, unstructured data around. Serialization is for people who don't trust their LLMs.
* **Embrace modern AI coding practices**: Leave everything up to an LLM to decide. The model knows best. Always.

    // Trigger any exception that the comparator would throw for the endpoints.
    /*
     * uncheckedCastNullableTToT is safe as long as the callers are careful to pass a "real" T
     * whenever they pass `true` for the matching `has*Bound` parameter.
     */
    if (hasLowerBound) {
      int unused =
          comparator.compare(

Dans le HTML qui contient :

{% raw %}

```jinja
Item ID: {{ id }}
```

{% endraw %}

... il affichera l’`id` récupéré à partir du `dict` « context » que vous avez passé :

```Python
{"id": id}
```

Par exemple, avec un ID de `42`, cela rendrait :

```html
Item ID: 42
```

### Arguments de `url_for` dans le template { #template-url-for-arguments }

    assertEquals(
        "Shouldn't catch any more events when unregistered.", expectedEvents, catcher2.getEvents());
  }

  // NOTE: This test will always pass if register() is thread-safe but may also
  // pass if it isn't, though this is unlikely.
  public void testRegisterThreadSafety() throws Exception {
    List<StringCatcher> catchers = new CopyOnWriteArrayList<>();

    assertEquals(
        "Shouldn't catch any more events when unregistered.", expectedEvents, catcher2.getEvents());
  }

  // NOTE: This test will always pass if register() is thread-safe but may also
  // pass if it isn't, though this is unlikely.
  public void testRegisterThreadSafety() throws Exception {
    List<StringCatcher> catchers = new CopyOnWriteArrayList<>();

Esto podría ser útil si, por ejemplo, vives en un país que restringe algunas URLs.

### Desactiva la documentación automática { #disable-the-automatic-docs }

El primer paso es desactivar la documentación automática, ya que por defecto, esos usan el CDN por defecto.

Para desactivarlos, establece sus URLs en `None` cuando crees tu aplicación de `FastAPI`:

#### Password hashing { #password-hashing }

"Hashing" means: converting some content (a password in this case) into a sequence of bytes (just a string) that looks like gibberish.

Whenever you pass exactly the same content (exactly the same password) you get exactly the same gibberish.

But you cannot convert from the gibberish back to the password.

##### Why use password hashing { #why-use-password-hashing }

  }

  @GwtIncompatible
  @J2ktIncompatible
  @Override
  public void refresh(K key) {
    delegate().refresh(key);
  }

  /**
   * A simplified version of {@link ForwardingLoadingCache} where subclasses can pass in an already
   * constructed {@link LoadingCache} as the delegate.
   *
   * @since 10.0
   */
  public abstract static class SimpleForwardingLoadingCache<K, V>
      extends ForwardingLoadingCache<K, V> {