En déclarant les types de vos variables, les éditeurs et outils peuvent vous offrir un meilleur support.

Ceci est un **tutoriel rapide / rappel** à propos des annotations de type Python. Il couvre uniquement le minimum nécessaire pour les utiliser avec **FastAPI** ... ce qui est en réalité très peu.

/// tip | Tipp

Auch die Integration anderer Authentifizierungs-/Autorisierungsanbieter wie Google, Facebook, X (Twitter), GitHub, usw. ist möglich und relativ einfach.

Das komplexeste Problem besteht darin, einen Authentifizierungs-/Autorisierungsanbieter wie solche aufzubauen, aber **FastAPI** reicht Ihnen die Tools, das einfach zu erledigen, während Ihnen die schwere Arbeit abgenommen wird.

///

/// tip

Integrating other authentication/authorization providers like Google, Facebook, X (Twitter), GitHub, etc. is also possible and relatively easy.

The most complex problem is building an authentication/authorization provider like those, but **FastAPI** gives you the tools to do it easily, while doing the heavy lifting for you.

///

## **FastAPI** utilities { #fastapi-utilities }

	r.expectedMax = expectedMax
}

// AddChecksum will add checksum checks as specified in
// https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html
// Returns ErrInvalidChecksum if a problem with the checksum is found.
func (r *Reader) AddChecksum(req *http.Request, ignoreValue bool) error {
	cs, err := GetContentChecksum(req.Header)
	if err != nil {
		return ErrInvalidChecksum
	}
	if cs == nil {

The first type parameter is for the keys of the `dict`.

The second type parameter is for the values of the `dict`:

{* ../../docs_src/python_types/tutorial008_py310.py hl[1] *}

This means:

* The variable `prices` is a `dict`:
    * The keys of this `dict` are of type `str` (let's say, the name of each item).
    * The values of this `dict` are of type `float` (let's say, the price of each item).

#### Union { #union }

    // <plugin/> block in a Maven POM. We have to do some wiggling to pull the sources of information
    // together and this really shows the problem of constructing a sensible default configuration, but
    // it's all encapsulated here so it appears normalized to the POM builder.

   * we've chosen to instead use a signature that benefits existing users -- and is still safe.
   *
   * For convertAll, I haven't looked as closely at *how* much existing users benefit, so we should
   * keep an eye out for problems that new users encounter. Note also that convertAll could support
   * both use cases by using @PolyNull. (By contrast, we can't use @PolyNull for our superinterface

 * ServerSocket} is closed even if the {@code MyServer} object is garbage-collected without calling
 * its {@code close} method. You could use a finalizer to accomplish this, but that has a
 * number of well-known problems. Here is how you might use this class instead:
 *
 * {@snippet :
 * public class MyServer implements Closeable {
 *   private static final FinalizableReferenceQueue frq = new FinalizableReferenceQueue();

    `@Deprecated` APIs will remain (again, unless they are `@Beta`). We have no
    plans to start removing things again, but officially, we're leaving our
    options open in case of surprises (like, say, a serious security problem).

3.  Guava has one dependency that is needed for linkage at runtime:
    `com.google.guava:failureaccess:1.0.3`. It also has
    [some annotation-only dependencies][guava-deps], which we discuss in more

#### 字典 { #dict }

定义 `dict` 时，需要传入 2 个类型参数，用逗号分隔。

第一个类型参数用于字典的键。

第二个类型参数用于字典的值：

{* ../../docs_src/python_types/tutorial008_py310.py hl[1] *}

这表示：

* 变量 `prices` 是一个 `dict`：
    * 这个 `dict` 的键是 `str` 类型（比如，每个条目的名称）。
    * 这个 `dict` 的值是 `float` 类型（比如，每个条目的价格）。

#### Union { #union }

你可以声明一个变量可以是若干种类型中的任意一种，比如既可以是 `int` 也可以是 `str`。