```Python
q: Union[str, None] = Query(default=None, max_length=50)
```

Cela va valider les données, montrer une erreur claire si ces dernières ne sont pas valides, et documenter le paramètre dans le schéma `OpenAPI` de cette *path operation*.

## Rajouter plus de validation

Vous pouvez aussi rajouter un second paramètre `min_length` :

{* ../../docs_src/query_params_str_validations/tutorial003.py hl[9] *}

## 調査

すべて既存の代替手段を使うことで、そのすべてを学び、アイデアを得て、自分や一緒に仕事をしてきた開発者のチームにとって最良の方法で組み合わせる機会を得ました。

たとえば、理想的にはPythonの標準的な型ヒントに基づくべきであることが明らかになりました。

また、すでにある規格を利用するのがベストな方法でした。

そこで、**FastAPI**のコードを書き始める前に、OpenAPI、JSON Schema、OAuth2などの仕様を数ヶ月かけて勉強し、それらの関係、重複する箇所、相違点を理解しました。

## 設計

その後、 (FastAPIを使う開発者として) ユーザーが欲しい「API」の設計に時間を費やしました。

もっとも人気のあるPythonエディターでいくつかのアイデアをテストしました。PyCharm、VS Code、Jediベースのエディターです。

///

## Integrated with OpenAPI { #integrated-with-openapi }

All the request declarations, validations and requirements of your dependencies (and sub-dependencies) will be integrated in the same OpenAPI schema.

So, the interactive docs will have all the information from these dependencies too:

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

## Simple usage { #simple-usage }

* ✨ Add support for disabling the separation of input and output JSON Schemas in OpenAPI with Pydantic v2 with `separate_input_output_schemas=False`. PR [#10145](https://github.com/tiangolo/fastapi/pull/10145) by [@tiangolo](https://github.com/tiangolo).
    * New docs [Separate OpenAPI Schemas for Input and Output or Not](https://fastapi.tiangolo.com/how-to/separate-openapi-schemas/).

    /**
     * Enumeration of model versions that can be validated.
     * These versions correspond to different levels of validation that can be applied
     * during model building, based on the POM schema version.
     * <p>
     * The validation levels are cumulative, with higher versions including all validations
     * from lower versions plus additional checks specific to that version.
     */
    enum Version {

   *
   * ```
   * 0b00xxxxxx Universal
   * 0b01xxxxxx Application
   * 0b10xxxxxx Context-Specific
   * 0b11xxxxxx Private
   * ```
   */
  var tagClass: Int,
  /** Identifies which member in the ASN.1 schema the field holds. */
  var tag: Long,
  /**
   * If the constructed bit is set it indicates that the value is composed of other values that have
   * their own headers.
   *

                    "200": {
                        "description": "Successful Response",
                        "content": {
                            "application/json": {
                                "schema": {}
                            }
                        }
                    }
                },
                "x-aperture-labs-portal": "blue"
            }
        }
    }
}
```

        * Nas respostas, o `set` será convertido para uma `list`.
        * O esquema gerado vai especificar que os valores do `set` são unicos (usando o `uniqueItems` do JSON Schema).
* `bytes`:
    * O `bytes` padrão do Python.
    * Em requisições e respostas será representado como uma `str`.
    * O esquema gerado vai especificar que é uma `str` com o "formato" `binary`.
* `Decimal`:

package schema

import (
	"bytes"
	"context"
	"database/sql"
	"database/sql/driver"
	"encoding/gob"
	"encoding/json"
	"fmt"
	"reflect"
	"strings"
	"sync"
	"time"
)

var serializerMap = sync.Map{}

// RegisterSerializer register serializer
func RegisterSerializer(name string, serializer SerializerInterface) {
	serializerMap.Store(strings.ToLower(name), serializer)
}

// GetSerializer get serializer

{* ../../docs_src/body_nested_models/tutorial005_py310.py hl[2,8] *}

The string will be checked to be a valid URL, and documented in JSON Schema / OpenAPI as such.

## Attributes with lists of submodels { #attributes-with-lists-of-submodels }

You can also use Pydantic models as subtypes of `list`, `set`, etc.: