**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

///

## Motivation { #motivation }

Let's start with a simple example:

{* ../../docs_src/python_types/tutorial001_py310.py *}

	jwtgo "github.com/golang-jwt/jwt/v4"
	jsoniter "github.com/json-iterator/go"
	"github.com/minio/minio/internal/bpool"
)

// SigningMethodHMAC - Implements the HMAC-SHA family of signing methods signing methods
// Expects key type of []byte for both signing and validation
type SigningMethodHMAC struct {
	Name       string
	Hash       crypto.Hash
	HasherPool bpool.Pool[hash.Hash]
}

// Specific instances for HS256, HS384, HS512

* [GitHub Issues](https://github.com/fastapi/fastapi/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+label%3Aquestion+-label%3Aanswered+)

多くの場合、その質問の答えをすでに知っているかもしれません。🤓

もし多くの人の質問に答えて助けてくれたなら、あなたは公式の[FastAPI Expert](fastapi-people.md#fastapi-experts)になります。🎉

最も大事なポイントは「親切であること」を心がけることです。人はフラストレーションを抱えてやって来るので、必ずしも最良の聞き方をしているとは限りませんが、できる限り親切に対応しましょう。🤗

**FastAPI** コミュニティは親切で歓迎的であることを目指しています。同時に、いじめや他者への無礼な振る舞いは受け入れないでください。お互いを大事にしましょう。

    )
    field_alias = (
        (field.validation_alias or field.alias)
        if field.mode == "validation"
        else (field.serialization_alias or field.alias)
    )

    # This expects that GenerateJsonSchema was already used to generate the definitions
    json_schema = field_mapping[(field, override_mode or field.mode)]
    if "$ref" not in json_schema:
        # TODO remove when deprecating Pydantic v1

		}, r.URL)
	case strings.HasPrefix(r.URL.Path, adminPathPrefix):
		var desc string
		version := extractAPIVersion(r)
		switch version {
		case "v1", madmin.AdminAPIVersionV2:
			desc = fmt.Sprintf("Server expects client requests with 'admin' API version '%s', found '%s', please upgrade the client to latest releases", madmin.AdminAPIVersion, version)
		case madmin.AdminAPIVersion:

   *   <li>If a constructor or factory method takes a parameter whose type is interface, a dynamic
   *       proxy will be passed to the method. It's possible that the method body expects an
   *       instance method of the passed-in proxy to be of a certain value yet the proxy isn't aware
   *       of the assumption, in which case the equality check before and after serialization will
   *       fail.

 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck/AbstractExecutorServiceTest.java?revision=1.30
 * which contained the following notice:
 *
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck/AbstractExecutorServiceTest.java?revision=1.30
 * which contained the following notice:
 *
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

Mais même si vous n'utilisez jamais **FastAPI**, vous auriez intérêt à en apprendre un peu à leur sujet.

/// note | Remarque

Si vous êtes un expert Python, et que vous savez déjà tout sur les annotations de type, passez au chapitre suivant.

///

## Motivation { #motivation }

Commençons par un exemple simple :

   *   <li>If a constructor or factory method takes a parameter whose type is interface, a dynamic
   *       proxy will be passed to the method. It's possible that the method body expects an
   *       instance method of the passed-in proxy to be of a certain value yet the proxy isn't aware
   *       of the assumption, in which case the equality check before and after serialization will
   *       fail.