**FastAPI** provides several tools to help you deal with **Security** easily, rapidly, in a standard way, without having to study and learn all the security specifications.

But first, let's check some small concepts.

## In a hurry?

// otherwise fallback to 'PodIP'.
//
// Note that very early in the pod's lifecycle (before all the node CNI plugin invocations finish)
// K8S may not have received the pod IPs yet, and may not report the pod as having any.
func GetPodIPsIfPresent(pod *corev1.Pod) []netip.Addr {
	var podIPs []netip.Addr
	if len(pod.Status.PodIPs) != 0 {
		for _, pip := range pod.Status.PodIPs {
			ip := netip.MustParseAddr(pip.IP)

  private static final ImmutableSet<String> NO_PS =
      ImmutableSet.of("www", "foo.ihopethiswillneverbeapublicsuffix", "x.y.z");

  /**
   * Having a public suffix is equivalent to having a registry suffix, because all registry suffixes
   * are public suffixes, and all public suffixes have registry suffixes.
   */
  private static final ImmutableSet<String> NO_RS = NO_PS;

These functions are there (instead of just using the classes directly) so that your editor doesn't mark errors about their types.

That way you can use your normal editor and coding tools without having to add custom configurations to disregard those errors.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

	healMRFMetaFormat    = 1
	healMRFMetaVersionV1 = 1
)

// PartialOperation is a successful upload/delete of an object
// but not written in all disks (having quorum)
type PartialOperation struct {
	Bucket              string
	Object              string
	VersionID           string
	Versions            []byte
	SetIndex, PoolIndex int
	Queued              time.Time

```Python hl_lines="10"
{!> ../../docs_src/query_params_str_validations/tutorial002_an.py!}
```

////

Notice that the default value is still `None`, so the parameter is still optional.

But now, having `Query(max_length=50)` inside of `Annotated`, we are telling FastAPI that we want it to have **additional validation** for this value, we want it to have maximum 50 characters. 😎

/// tip

like having a game of play with a cart-horse, and expecting every
moment to be trampled under its feet, ran round the thistle
again; then the puppy began a series of short charges at the
stick, running a very little way forwards each time and a long
way back, and barking hoarsely all the while, till at last it sat
down a good way off, panting, with its tongue hanging out of its
mouth, and its great eyes half shut.

import okhttp3.internal.assertNotHeld
import okhttp3.internal.okHttpName

/**
 * A set of tasks that are executed in sequential order.
 *
 * Work within queues is not concurrent. This is equivalent to each queue having a dedicated thread
 * for its work; in practice a set of queues may share a set of threads to save resources.
 */
class TaskQueue internal constructor(
  internal val taskRunner: TaskRunner,
  internal val name: String,

```

...this would work:

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

And of course, you can define some parameters as required, some as having a default value, and some entirely optional:

//// tab | Python 3.10+

```Python hl_lines="8"
{!> ../../docs_src/query_params/tutorial006_py310.py!}
```

////

//// tab | Python 3.8+