Python has support for optional "type hints" (also called "type annotations").

These **"type hints"** or annotations are a special syntax that allow declaring the <abbr title="for example: str, int, float, bool">type</abbr> of a variable.

By declaring types for your variables, editors and tools can give you better support.

Estos **type hints** son una nueva sintaxis, desde Python 3.6+, que permite declarar el <abbr title="por ejemplo: str, int, float, bool">tipo</abbr> de una variable.

Usando las declaraciones de tipos para tus variables, los editores y otras herramientas pueden proveerte un soporte mejor.

Daarnaast betekent het ook dat je code zeer verenigbaar zal zijn met veel andere Python-hulpmiddelen en -pakketten. 🚀

///

## Type hints in **FastAPI**

**FastAPI** maakt gebruik van type hints om verschillende dingen te doen.

Met **FastAPI** declareer je parameters met type hints en krijg je:

* **Editor ondersteuning**.
* **Type checks**.

...en **FastAPI** gebruikt dezelfde declaraties om:

Esses **"type hints"** são uma sintaxe especial que permite declarar o <abbr title = "por exemplo: str, int, float, bool">tipo</abbr> de uma variável.

Ao declarar tipos para suas variáveis, editores e ferramentas podem oferecer um melhor suporte.

     *            dominant data.
     * @param hints A set of key-value pairs that customized merger implementations can use to carry domain-specific
     *            information along, may be <code>null</code>.
     */
    public void merge(
            org.apache.maven.model.Model target,
            org.apache.maven.model.Model source,
            boolean sourceDominant,
            Map<?, ?> hints) {

It had automatic data validation, data serialization and OpenAPI schema generation based on the same type hints in several places.

  /**
   * The HTTP <a href="https://wicg.github.io/ua-client-hints/#sec-ch-ua-arch">{@code
   * Sec-CH-UA-Arch}</a> header field name.
   *
   * @since 30.0
   */
  public static final String SEC_CH_UA_ARCH = "Sec-CH-UA-Arch";
  /**
   * The HTTP <a href="https://wicg.github.io/ua-client-hints/#sec-ch-ua-model">{@code
   * Sec-CH-UA-Model}</a> header field name.
   *
   * @since 30.0

        Map<Object, Object> hints = new HashMap<>();
        String childPath = child.getProperties().getOrDefault(CHILD_DIRECTORY_PROPERTY, child.getArtifactId());
        hints.put(CHILD_DIRECTORY, childPath);
        hints.put(MavenModelMerger.CHILD_PATH_ADJUSTMENT, getChildPathAdjustment(child, parent, childPath));
        return merger.merge(child, parent, false, hints);
    }

    /**

C'était l'une des premières implémentations d'un framework utilisant les type hints Python pour déclarer les paramètres
et les requêtes que j'ai vues (avant NestJS et Molten). Je l'ai trouvé plus ou moins en même temps que Hug. Mais APIStar utilisait le standard OpenAPI.

Il disposait de la validation automatique, sérialisation des données et d'une génération de schéma OpenAPI basée sur les mêmes type hints à plusieurs endroits.

</blockquote>

## Investigation

By using all the previous alternatives I had the chance to learn from all of them, take ideas, and combine them in the best way I could find for myself and the teams of developers I have worked with.

For example, it was clear that ideally it should be based on standard Python type hints.