}

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1;
  }

  /**
   * Returns a serializable converter object that converts between strings and integers using {@link
   * Integer#decode} and {@link Integer#toString()}. The returned converter throws {@link
   * NumberFormatException} if the input string is invalid.
   *

///

## Dataclasses en `response_model`

También puedes usar `dataclasses` en el parámetro `response_model`:

{* ../../docs_src/dataclasses/tutorial002.py hl[1,7:13,19] *}

El dataclass será automáticamente convertido a un dataclass de Pydantic.

De esta manera, su esquema aparecerá en la interfaz de usuario de la documentación de la API:

<img src="/img/tutorial/dataclasses/image01.png">

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1;
  }

  /**
   * Returns a serializable converter object that converts between strings and floats using {@link
   * Float#valueOf} and {@link Float#toString()}.
   *
   * @since 16.0
   */
  public static Converter<String, Float> stringConverter() {
    return FloatConverter.INSTANCE;
  }

  /**

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1;
  }

  /**
   * Returns a serializable converter object that converts between strings and doubles using {@link
   * Double#valueOf} and {@link Double#toString()}.
   *
   * @since 16.0
   */
  public static Converter<String, Double> stringConverter() {
    return DoubleConverter.INSTANCE;
  }

  /**

            "msg": "value is not a valid integer",
            "type": "type_error.integer"
        }
    ]
}
```

car le paramètre de chemin `item_id` possède comme valeur `"foo"`, qui ne peut pas être convertie en entier (`int`).

La même erreur se produira si vous passez un nombre flottant (`float`) et non un entier, comme ici

            }
        }
        return defaultValue;
    }

    /**
     * Converts an object to the specified class type.
     * @param <T> The target type.
     * @param value The object to convert.
     * @param clazz The class type to convert to.
     * @return The converted object.
     */
    @SuppressWarnings("unchecked")

{"item_id":3}
```

/// check | Revisa

Nota que el valor que tu función recibió (y devolvió) es `3`, como un `int` de Python, no un string `"3"`.

Entonces, con esa declaración de tipo, **FastAPI** te ofrece <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr> automático de requests.

///

## Validación de datos

{"item_id":3}
```

/// check

Notice that the value your function received (and returned) is `3`, as a Python `int`, not a string `"3"`.

So, with that type declaration, **FastAPI** gives you automatic request <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>.

///

## Data validation { #data-validation }

   *     specified is substituted for the first occurrence of {@code "%s"} in the template, and so
   *     forth. A {@code null} argument is converted to the four-character string {@code "null"};
   *     non-null values are converted to strings using {@link Object#toString()}.
   * @since 25.1
   */
  // TODO(diamondm) consider using Arrays.toString() for array parameters
  public static String lenientFormat(

        }
        return targetList;
    }

    /**
     * Extracts a field value from OpenSearch results and converts it to the specified type.
     *
     * @param <T> The target type.
     * @param field The field value from OpenSearch.
     * @param clazz The target class.
     * @return The converted field value.
     */
    @SuppressWarnings("unchecked")