但 FastAPI 还可以使用数据类（<a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a>）：

{* ../../docs_src/dataclasses_/tutorial001.py hl[1,7:12,19:20] *}

这还是借助于 **Pydantic** 及其<a href="https://pydantic-docs.helpmanual.io/usage/dataclasses/#use-of-stdlib-dataclasses-with-basemodel" class="external-link" target="_blank">内置的 `dataclasses`</a>。

```

Or environment variables

```
KEY:
notify_amqp[:name]  publish bucket notifications to AMQP endpoints

ARGS:
MINIO_NOTIFY_AMQP_ENABLE*        (on|off)    enable notify_amqp target, default is 'off'
MINIO_NOTIFY_AMQP_URL*           (url)       AMQP server endpoint e.g. `amqp://myuser:mypassword@localhost:5672`
MINIO_NOTIFY_AMQP_EXCHANGE       (string)    name of the AMQP exchange

Der eigentliche Callback ist nur ein HTTP-Request.

Wenn Sie den Callback selbst implementieren, können Sie beispielsweise <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> oder <a href="https://requests.readthedocs.io/" class="external-link" target="_blank">Requests</a> verwenden.

///

## Schreiben des Codes, der den Callback dokumentiert { #write-the-callback-documentation-code }

* [Внутренняя ссылка](index.md#installation){.internal-link target=_blank}
* <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">Внешняя ссылка</a>
* <a href="https://fastapi.tiangolo.com/css/styles.css" class="external-link" target="_blank">Ссылка на стиль</a>
* <a href="https://fastapi.tiangolo.com/js/logic.js" class="external-link" target="_blank">Ссылка на скрипт</a>

### `pydantic-settings` installieren { #install-pydantic-settings }

Stellen Sie zunächst sicher, dass Sie Ihre [virtuelle Umgebung](../virtual-environments.md){.internal-link target=_blank} erstellt und aktiviert haben, und installieren Sie dann das Package `pydantic-settings`:

                  <artifactId>maven-api-model</artifactId>
                  <version>4.0.0-alpha-1-SNAPSHOT</version>
                  <type>mdo</type>
                  <outputDirectory>target/mdo/</outputDirectory>
                  <destFileName>maven.mdo</destFileName>
                </artifactItem>
              </artifactItems>
            </configuration>
          </execution>
        </executions>

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**
 * This annotation will mark your class as a Mojo, which is the implementation of a goal in a Maven plugin.

## 結論

透過這個教學，你應該對**環境變數**是什麼以及如何在 Python 中使用它們有了基本的了解。

你也可以在<a href="https://zh.wikipedia.org/wiki/%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F" class="external-link" target="_blank">環境變數 - 維基百科</a> (<a href="https://en.wikipedia.org/wiki/Environment_variable" class="external-link" target="_blank">Wikipedia for Environment Variable</a>) 中了解更多關於它們的資訊。

在許多情況下，環境變數的用途和適用性可能不會立刻顯現。但是在開發過程中，它們會在許多不同的場景中出現，因此瞭解它們是非常必要的。

### Target language

Translate to Simplified Chinese (简体中文).

Language code: zh.

### Grammar and tone

1) Use clear, concise technical Chinese consistent with existing docs.
2) Address the reader naturally (commonly using “你/你的”).

### Headings

1) Follow existing Simplified Chinese heading style (short and descriptive).
2) Do not add trailing punctuation to headings.

import java.lang.annotation.Target;

import com.google.inject.ScopeAnnotation;

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Indicates that annotated component should be instantiated before session execution starts
 * and discarded after session execution completes.
 *
 * @since 3.2.0
 */
@Target({TYPE})
@Retention(RUNTIME)