And also that your code will be very compatible with many other Python tools and libraries. 🚀

///

## Type hints in **FastAPI** { #type-hints-in-fastapi }

**FastAPI** takes advantage of these type hints to do several things.

With **FastAPI** you declare parameters with type hints and you get:

* **Editor support**.
* **Type checks**.

...and **FastAPI** uses the same declarations to:

E também que o seu código será muito compatível com diversas outras ferramentas e bibliotecas Python. 🚀

///

## Type hints no **FastAPI** { #type-hints-in-fastapi }

O **FastAPI** aproveita esses type hints para fazer várias coisas.

Com o **FastAPI**, você declara parâmetros com type hints e obtém:

* **Suporte ao editor**.
* **Verificações de tipo**.

... e o **FastAPI** usa as mesmas declarações para:

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

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.

        «««
        ## Type hints and annotations { #type-hints-and-annotations }
        »»»

    Translate with (German) – notice the hyphen:

        «««
        ## Typhinweise und -annotationen { #type-hints-and-annotations }
        »»»

    Do NOT translate with (German) – notice the dash:

        «««
        ## Typhinweise und –annotationen { #type-hints-and-annotations }
        »»»

</blockquote>

## Investigation { #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.

      // actual response status.
      code == 100 -> true

      // Handle Processing (102) & Early Hints (103) and any new codes without failing
      // 100 and 101 are the exceptions with different meanings
      // But Early Hints not currently exposed
      code in (102 until 200) -> true

      else -> false
    }

* Transactions, Nested Transactions, Save Point, RollbackTo to Saved Point
* Context, Prepared Statement Mode, DryRun Mode
* Batch Insert, FindInBatches, Find To Map
* SQL Builder, Upsert, Locking, Optimizer/Index/Comment Hints, NamedArg, Search/Update/Create with SQL Expr
* Composite Primary Key
* Auto Migrations
* Logger
* Extendable, flexible plugin API: Database Resolver (Multiple Databases, Read/Write Splitting) / Prometheus…

>
> 하지만 결국에는 이 모든 기능을 통합하는 도구가 필요해졌습니다. 이전 도구들로부터 최고의 아이디어들을 모으고, 이를 최적의 방식으로 조합해야만 했습니다. 이는 :term:Python 3.6+ 타입 힌트 <type hints>와 같은, 이전에는 사용할 수 없었던 언어 기능이 가능했기 때문입니다.

---

## 조사

여러 대안을 사용해 보며 다양한 도구에서 배운 점들을 모아 저와 개발팀에게 가장 적합한 방식을 찾았습니다.

예를 들어, 표준 :term:Python 타입 힌트 <type hints>에 기반하는 것이 이상적이라는 점이 명확했습니다.

또한, 이미 존재하는 표준을 활용하는 것이 가장 좋은 접근법이라 판단했습니다.

# Introducción a Tipos en Python { #python-types-intro }

Python tiene soporte para "anotaciones de tipos" opcionales (también llamadas "type hints").

Estas **"anotaciones de tipos"** o type hints son una sintaxis especial que permite declarar el <abbr title="por ejemplo: str, int, float, bool">tipo</abbr> de una variable.

Al declarar tipos para tus variables, los editores y herramientas te pueden proporcionar un mejor soporte.