```console
// Crea una env var MY_NAME en línea para esta llamada del programa
$ MY_NAME="Wade Wilson" python main.py

// Ahora puede leer la variable de entorno

Hello Wade Wilson from Python

// La env var ya no existe después
$ python main.py

Hello World from Python
```

</div>

/// tip | Consejo

/**
 * A semi-persistent mapping from keys to values. Cache entries are manually added using {@link
 * #get(Object, Callable)} or {@link #put(Object, Object)}, and are stored in the cache until either
 * evicted or manually invalidated. The common way to build instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *

En este caso, el path original `/app` realmente sería servido en `/api/v1/app`.

Aunque todo tu código esté escrito asumiendo que solo existe `/app`.

{* ../../docs_src/behind_a_proxy/tutorial001_py39.py hl[6] *}

Estos tipos que tienen tipos internos se denominan tipos "**genéricos**". Y es posible declararlos, incluso con sus tipos internos.

Para declarar esos tipos y los tipos internos, puedes usar el módulo estándar de Python `typing`. Existe específicamente para soportar estas anotaciones de tipos.

#### Versiones más recientes de Python { #newer-versions-of-python }

---

Pour revenir à l'exemple de code précédent, **FastAPI** permet de :

* Valider que `item_id` existe dans le chemin des requêtes `GET` et `PUT`.
* Valider que `item_id` est de type `int` pour les requêtes `GET` et `PUT`.
    * Si ce n'est pas le cas, le client voit une erreur utile et claire.
* Vérifier qu'il existe un paramètre de requête facultatif nommé `q` (comme dans `http://127.0.0.1:8000/items/foo?q=somequery`) pour les requêtes `GET`.

	return c.client.ImportKey(ctx, keyID, &kes.ImportKeyRequest{
		Key: bytes,
	})
}

// EncryptKey Encrypts and authenticates a (small) plaintext with the cryptographic key
// The plaintext must not exceed 1 MB
func (c *kesConn) EncryptKey(keyID string, plaintext []byte, ctx Context) ([]byte, error) {
	ctxBytes, err := ctx.MarshalText()
	if err != nil {
		return nil, err
	}

    CacheTesting.checkValidState(cache);
  }

  /**
   * Tests that when a single entry exceeds the segment's max weight, the new entry is immediately
   * evicted and nothing else.
   */
  public void testEviction_maxWeight_entryTooBig() {
    CountingRemovalListener<Integer, Integer> removalListener = countingRemovalListener();
    IdentityLoader<Integer> loader = identityLoader();

And if you update that local FastAPI source code when you run that Python file again, it will use the fresh version of FastAPI you just edited.

That way, you don't have to "install" your local version to be able to test every change.

/// note | Technical Details

      else -> {
        toEvict = null
        toEvictIdleAtNs = -1L
      }
    }

    when {
      toEvict != null -> {
        // We've chosen a connection to evict. Confirm it's still okay to be evicted, then close it.
        toEvict.withLock {
          if (toEvict.calls.isNotEmpty()) return 0L // No longer idle.
          if (toEvict.idleAtNs != toEvictIdleAtNs) return 0L // No longer oldest.

     * <p>
     * If there are Maven3 passwords presents in settings, this results in doubled warnings emitted. So Plexus DI
     * creation call keeps "emitSettingsWarnings" false. If there are fatal issues, it will anyway "die" at that
     * spot before warnings would be emitted.
     * <p>
     * The method returns a "cleaner" runnable, as during extension loading the context needs to be "cleaned", restored