Si tienes bastante conocimiento técnico (coroutines, hilos, bloqueo, etc.) y tienes curiosidad sobre cómo FastAPI maneja `async def` vs `def` normal, adelante.

///

### Funciones de *path operation*

Cuando declaras una *path operation function* con `def` normal en lugar de `async def`, se ejecuta en un threadpool externo que luego es esperado, en lugar de ser llamado directamente (ya que bloquearía el servidor).

                && method.getParameterTypes().length == 0;
    }

    /**
     * Returns the element type of the parameterized collection declared as the method's argument type.
     *
     * @param method
     *            The method. Cannot be {@literal null}
     * @param position

```JSON
{
    "name": "Foo",
    "price": 45.2
}
```

## Déclarez-le comme paramètre

Pour l'ajouter à votre *opération de chemin*, déclarez-le comme vous déclareriez des paramètres de chemin ou de requête :

{* ../../docs_src/body/tutorial001.py hl[18] *}

...et déclarez que son type est le modèle que vous avez créé : `Item`.

## Résultats

///

{* ../../docs_src/security/tutorial005_an_py310.py hl[157] *}

## Declare scopes in *path operations* and dependencies { #declare-scopes-in-path-operations-and-dependencies }

Now we declare that the *path operation* for `/users/me/items/` requires the scope `items`.

For this, we import and use `Security` from `fastapi`.

Pour que `await` fonctionne, il doit être placé dans une fonction qui supporte l'asynchronicité. Pour que ça soit le cas, il faut déclarer cette dernière avec `async def` :

```Python hl_lines="1"
async def get_burgers(number: int):
    # Opérations asynchrones pour créer les burgers
    return burgers
```

...et non `def` :

q: Annotated[str | None, Query(min_length=3)] = None
```

////

So, when you need to declare a value as required while using `Query`, you can simply not declare a default value:

{* ../../docs_src/query_params_str_validations/tutorial006_an_py39.py hl[9] *}

### Required, can be `None` { #required-can-be-none }

        verifyNoInteractions(mocked);
    }

    // Reflection-based check: ensure serialVersionUID remains the declared constant
    @Test
    @DisplayName("serialVersionUID matches declared constant")
    void serialVersionUID_hasExpectedValue() throws Exception {
        // Arrange
        Field f = SMBSignatureValidationException.class.getDeclaredField("serialVersionUID");

  }

  /**
   * Returns {@code true} if this is an overridable method. Constructors, private, static or final
   * methods, or methods declared by final classes are not overridable.
   */
  public abstract boolean isOverridable();

  /** Returns {@code true} if this was declared to take a variable number of arguments. */
  public abstract boolean isVarArgs();

  /**

   *   <li>If there is any non-private constructor or non-private static factory method declared by
   *       {@code cls}, all non-private instance methods will be checked too using the instance
   *       created by invoking the constructor or static factory method.
   *   <li>If there is any non-private constructor or non-private static factory method declared by
   *       {@code cls}:
   *       <ul>

* A documentação alternativa também irá refletir o novo parâmetro da _query_ e o corpo:

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Recapitulando

Resumindo, você declara **uma vez** os tipos dos parâmetros, corpo etc. como parâmetros de função.

Você faz isso com os tipos padrão do Python moderno.