É isso que vamos resolver: vamos carregar o modelo antes de as requisições serem tratadas, mas apenas um pouco antes de a aplicação começar a receber requisições, não enquanto o código estiver sendo carregado.

   * the caller when the timeout elapses; aborting the target method call is of secondary concern.
   * The particular nature and strength of the guarantees made by the proxy is
   * implementation-dependent. However, it is important that each of the methods on the target
   * object behaves appropriately when its thread is interrupted.
   *
   * <p>For example, to return the value of {@code target.someMethod()}, but substitute {@code

  ConcurrentMap<K, V> asMap();

  /**
   * Performs any pending maintenance operations needed by the cache. Exactly which activities are
   * performed -- if any -- is implementation-dependent.
   */
  void cleanUp();

Le « flux » `password` est l'une des manières (« flows ») définies dans OAuth2 pour gérer la sécurité et l'authentification.

OAuth2 a été conçu pour que le backend ou l'API puisse être indépendant du serveur qui authentifie l'utilisateur.

Mais dans ce cas, la même application **FastAPI** gérera l'API et l'authentification.

Voyons cela selon ce point de vue simplifié :

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

/**
 * A convenience base class for implementors of {@code Hasher}; handles accumulating data until an
 * entire "chunk" (of implementation-dependent length) is ready to be hashed.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 */
// TODO(kevinb): this class still needs some design-and-document-for-inheritance love

  ImmediateExecutionOperation* CreateOperation() override = 0;

  // Returns whether the runtime is backed by TFRT or the legacy TF Eager
  // Runtime. This is necessary to decouple runtime-dependent
  // code that is layered on top of the runtime.
  virtual bool UsesTFRT() = 0;

  // List attributes of available devices
  virtual void ListDevices(std::vector<DeviceAttributes>* devices) = 0;

    /**
     * Expands a version range to a list of matching versions, in ascending order.
     * For example, resolves "[3.8,4.0)" to "3.8", "3.8.1", "3.8.2".
     * The returned list of versions is only dependent on the configured repositories and their contents.
     * The supplied request may also refer to a single concrete version rather than a version range.

### Le problème { #the-problem }

Alors, quel est le problème d’installer des packages dans l’environnement Python global ?

À un moment donné, vous finirez probablement par écrire de nombreux programmes différents qui dépendent de packages différents. Et certains de ces projets sur lesquels vous travaillez dépendront de versions différentes du même package. 😱

   *
   * <p>Note: in principle this should never need to be used, but it might be useful if the
   * semantics of an implementation disagree in unforeseen ways with the semantics expected by a
   * test, or to keep dependent builds clean in spite of an erroneous test.
   */
  @CanIgnoreReturnValue
  public B suppressing(Method... methods) {
    return suppressing(asList(methods));
  }

  @CanIgnoreReturnValue

Isso foi alterado no FastAPI 0.106.0 com a intenção de não manter recursos enquanto se espera a response percorrer a rede.

/// tip | Dica

Além disso, uma tarefa em segundo plano normalmente é um conjunto de lógica independente que deve ser tratado separadamente, com seus próprios recursos (por exemplo, sua própria conexão de banco de dados).

Assim, desta forma você provavelmente terá um código mais limpo.

///