El valor **por defecto** del **parámetro de función** es el valor **real por defecto**, eso es más intuitivo con Python en general. 😌

        return;
      }
      // First, check whether var -> arg forms a cycle
      for (Type t = arg; t != null; t = mappings.get(TypeVariableKey.forLookup(t))) {
        if (var.equalsType(t)) {
          // cycle detected, remove the entire cycle from the mapping so that
          // each type variable resolves deterministically to itself.
          // Otherwise, an F -> T cycle will end up resolving both F and T

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

O uso de `Optional[str]` em vez de apenas `str` permitirá que o editor o ajude a detectar erros, onde você pode estar assumindo que um valor é sempre um `str`, quando na verdade também pode ser `None`.

`Optional[Something]` é na verdade um atalho para `Union[Something, None]`, eles são equivalentes.

combinator to prevent styles leaking to nested tables which doesn't have a `.table` class.\n  // We use the universal selectors here to simplify the selector (else we would need 6 different selectors).\n  // Another advantage is that this generates less code and makes the selector less specific making it easier to override.\n  // stylelint-disable-next-line selector-max-universal\n  > :not(caption) > * > * {\n    padding: $table-cell-padding-y $table-cell-padding-x;\n    // Following the precept of cascades:...

* Un script de bash que ejecuta los pasos previos y luego inicia tu aplicación
    * Aún necesitarías una forma de iniciar/reiniciar *ese* script de bash, detectar errores, etc.

/// tip | Consejo

Te daré más ejemplos concretos para hacer esto con contenedores en un capítulo futuro: [FastAPI en Contenedores - Docker](docker.md){.internal-link target=_blank}.

///

- Fixed an issue to not drain all the pods in a namespace when an empty-selector i.e. "{}" is specified in a Pod Disruption Budget (PDB) ([#121132](https://github.com/kubernetes/kubernetes/pull/121132), [@sairameshv](https://github.com/sairameshv)) [SIG Apps]

### Existing object replication

/// note

FastAPI will know that the value of `q` is not required because of the default value `= None`.

Having `str | None` will allow your editor to give you better support and detect errors.

///

## Additional validation { #additional-validation }

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

    NodeAndRemainingSuccessors(N node) {
      this.node = node;
    }
  }

  /**
   * Determines whether an edge has already been used during traversal. In the directed case a cycle
   * is always detected before reusing an edge, so no special logic is required. In the undirected
   * case, we must take care not to "backtrack" over an edge (i.e. going from A to B and then going
   * from B to A).
   */

    NodeAndRemainingSuccessors(N node) {
      this.node = node;
    }
  }

  /**
   * Determines whether an edge has already been used during traversal. In the directed case a cycle
   * is always detected before reusing an edge, so no special logic is required. In the undirected
   * case, we must take care not to "backtrack" over an edge (i.e. going from A to B and then going
   * from B to A).
   */