//// tab | Python 3.10+

```Python hl_lines="26-27  30"
{!> ../../docs_src/dependency_testing/tutorial001_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="28-29  32"
{!> ../../docs_src/dependency_testing/tutorial001_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="29-30  33"

  private static final Escaper HTML_ESCAPER =
      Escapers.builder()
          .addEscape('"', """)
          // Note: "'" is not defined in HTML 4.01.
          .addEscape('\'', "'")
          .addEscape('&', "&")
          .addEscape('<', "&lt;")
          .addEscape('>', "&gt;")
          .build();

  private HtmlEscapers() {}

```Python hl_lines="10"
{!../../docs_src/settings/app02/config.py!}
```

请注意，现在我们不创建默认实例 `settings = Settings()`。

### 主应用程序文件

现在我们创建一个依赖项，返回一个新的 `config.Settings()`。

//// tab | Python 3.9+

```Python hl_lines="6  12-13"
{!> ../../docs_src/settings/app02_an_py39/main.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="6  12-13"

    weakHashLength32WithSeeds(bytes, offset + length - 64, length, y, v);
    weakHashLength32WithSeeds(bytes, offset + length - 32, length * K1, K0, w);
    z += shiftMix(v[1]) * K1;
    x = rotateRight(z + x, 39) * K1;
    y = rotateRight(y, 33) * K1;

    // Decrease length to the nearest multiple of 64, and operate on 64-byte chunks.
    length = (length - 1) & ~63;
    do {

            checkout scm
        }

        def WORK_DIR=pwd()
        def MAVEN_GOAL='verify'

        stage('Configure deploy') {
           if (env.BRANCH_NAME in ['master', 'maven-3.8.x', 'maven-3.9.x']){
               MAVEN_GOAL='deploy'
           }
        }

        stage('Build / Unit Test') {
            String jdkName = jenkinsEnv.jdkFromVersion(buildOs, buildJdk)

**FastAPI** 知道在每种情况下该做什么以及如何复用同一对象，因此所有后台任务被合并在一起并且随后在后台运行：

//// tab | Python 3.10+

```Python hl_lines="13  15  22  25"
{!> ../../docs_src/background_tasks/tutorial002_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="13  15  22  25"
{!> ../../docs_src/background_tasks/tutorial002_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="14  16  23  26"

比如，你可以将请求体的一个 `example` 传递给 `Body`:

//// tab | Python 3.10+

```Python hl_lines="22-27"
{!> ../../docs_src/schema_extra_example/tutorial003_an_py310.py!}
```

////

//// tab | Python 3.9+

```Python hl_lines="22-27"
{!> ../../docs_src/schema_extra_example/tutorial003_an_py39.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="23-28"

    A4IBAQCT1DCw1wMgKtD5Y+iRDAUgqV8ZyntyTtSx29CW+1RaGSwMCPeyvIWonX9t
    O1KzKtvn1ISMY/YPyyYBkVBs9F8U4pN0wBOeMDpQ47RgxRzwIkSNcUesyBrJ6Zua
    AGAT/3B+XxFNSRuzFVJ7yVTav52Vr2ua2J7p8eRDjeIRRDq/r72DQnNSi6q7pynP
    9WQcCk3RvKqsnyrQ/39/2n3qse0wJcGE2jTSW3iDVuycNsMm4hH2Z0kdkquM++v/
    eu6FSqdQgPCnXEqULl8FmTxSQeDNtGPPAUO6nIPcj2A781q0tHuu2guQOHXvgR1m
    0vdXcDazv/wor3ElhVsT/h5/WrQ8
    -----END CERTIFICATE-----
    """.trimIndent().decodeCertificatePem()

Perceba que dessa vez não criamos uma instância padrão `settings = Settings()`.

### O arquivo principal da aplicação

Agora criamos a dependência que retorna um novo objeto `config.Settings()`.

//// tab | Python 3.9+

```Python hl_lines="6  12-13"
{!> ../../docs_src/settings/app02_an_py39/main.py!}
```

////

//// tab | Python 3.8+

```Python hl_lines="6  12-13"

有个 `POST` 操作会返回一些错误。

所有*路径操作* 都需要一个`X-Token` 头。

//// tab | Python 3.10+

```Python
{!> ../../docs_src/app_testing/app_b_an_py310/main.py!}
```

////

//// tab | Python 3.9+

```Python
{!> ../../docs_src/app_testing/app_b_an_py39/main.py!}
```

////

//// tab | Python 3.8+

```Python
{!> ../../docs_src/app_testing/app_b_an/main.py!}
```

////