Most of these settings are variable (can change), like database URLs. And many could be sensitive, like secrets.

For this reason it's common to provide them in environment variables that are read by the application.

/// tip

To understand environment variables you can read [Environment Variables](../environment-variables.md){.internal-link target=_blank}.

///

## Types and validation { #types-and-validation }

    if [ -z $FILENAME ]; then
      ${MC} admin user svcacct add --access-key $(head -1 $MINIO_ACCESSKEY_SECRETKEY_TMP) --secret-key $(tail -n1 $MINIO_ACCESSKEY_SECRETKEY_TMP) myminio $USER
    else
      ${MC} admin user svcacct add --access-key $(head -1 $MINIO_ACCESSKEY_SECRETKEY_TMP) --secret-key $(tail -n1 $MINIO_ACCESSKEY_SECRETKEY_TMP) --policy /config/$FILENAME.json myminio $USER
    fi
  else
    echo "Svcacct '$SVCACCT' already exists."

        assertTrue(str.contains("1024"));
    }

    /**
     * Test FileEndOfFileInformation encode/decode round trip
     */
    @Test
    @DisplayName("Test FileEndOfFileInformation encode/decode round trip")
    void testFileEndOfFileInformationEncodeDecodeRoundTrip() throws SMBProtocolDecodingException {
        long originalValue = 0x123456789ABCDEFL;

Эта часть вполне обычна, большая часть кода вам уже знакома:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip | Совет

Query-параметр `callback_url` использует тип Pydantic <a href="https://docs.pydantic.dev/latest/api/networks/" class="external-link" target="_blank">Url</a>.

///

```

</div>

////

/// tip | 팁

가상 환경에 새로운 패키지를 설치할 때마다, 해당 환경을 다시 활성화하세요.

이렇게 하면 해당 패키지로 설치된 **터미널(<abbr title="command line interface">CLI</abbr>) 프로그램**을 사용할 때, 전역에 설치된 다른 버전이 아니라, 가상 환경 안에 설치된 정확한 버전을 사용합니다.

///

## 가상 환경이 활성화 여부 확인

가상 환경이 활성화되었는지 확인합니다. (이전 명령어가 제대로 작동했는지 확인합니다).

/// tip | 팁

这种做法相当常见，有一个名称，这些环境变量通常放在一个名为 `.env` 的文件中，该文件被称为“dotenv”。

/// tip

以点 (`.`) 开头的文件是 Unix-like 系统（如 Linux 和 macOS）中的隐藏文件。

但是，dotenv 文件实际上不一定要具有确切的文件名。

///

Pydantic 支持使用外部库从这些类型的文件中读取。您可以在<a href="https://docs.pydantic.dev/latest/concepts/pydantic_settings/#dotenv-env-support" class="external-link" target="_blank">Pydantic 设置: Dotenv (.env) 支持</a>中阅读更多相关信息。

/// tip

要使其工作，您需要执行 `pip install python-dotenv`。

///

/// tip

You would normally do this **once**, right after you create the virtual environment.

///

Make sure the virtual environment is active (with the command above) and then run:

<div class="termy">

```console
$ python -m pip install --upgrade pip

---> 100%
```

</div>

/// tip

Dieser Teil ist ziemlich normal, der größte Teil des Codes ist Ihnen wahrscheinlich bereits bekannt:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip | Tipp

Der Query-Parameter `callback_url` verwendet einen Pydantic-<a href="https://docs.pydantic.dev/latest/api/networks/" class="external-link" target="_blank">Url</a>-Typ.

///

</div>

## In Detail { #in-detail }

The marker `@pytest.mark.anyio` tells pytest that this test function should be called asynchronously:

{* ../../docs_src/async_tests/app_a_py39/test_main.py hl[7] *}

/// tip

Note that the test function is now `async def` instead of just `def` as before when using the `TestClient`.

///

Then we can create an `AsyncClient` with the app, and send async requests to it, using `await`.

{
    "ok": true
}
```

/// tip | 提示

注意，回调 URL包含 `callback_url` （`https://www.external.org/events`）中的查询参数，还有 JSON 请求体内部的发票 ID（`2expen51ve`）。

///

### 添加回调路由

至此，在上文创建的回调路由里就包含了*回调路径操作*（外部开发者要在外部 API 中实现）。

现在使用 API *路径操作装饰器*的参数 `callbacks`，从回调路由传递属性 `.routes`（实际上只是路由/路径操作的**列表**）：

{* ../../docs_src/openapi_callbacks/tutorial001.py hl[36] *}

/// tip | 提示