### 使用 `app.dependency_overrides` 属性

对于这些用例，**FastAPI** 应用支持 `app.dependcy_overrides` 属性，该属性就是**字典**。

要在测试时覆盖原有依赖项，这个字典的键应当是原依赖项（函数），值是覆盖依赖项（另一个函数）。

这样一来，**FastAPI** 就会调用覆盖依赖项，不再调用原依赖项。

```Python hl_lines="26-27  30"
{!../../../docs_src/dependency_testing/tutorial001.py!}
```

!!! tip "提示"

    **FastAPI** 应用中的任何位置都可以实现覆盖依赖项。

    原依赖项可用于*路径操作函数*、*路径操作装饰器*（不需要返回值时）、`.include_router()` 调用等。

=== "Python 3.9+"

    ```Python hl_lines="26-30"
    {!> ../../../docs_src/security/tutorial007_an_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="26-30"
    {!> ../../../docs_src/security/tutorial007_an.py!}
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip

# Static Files

You can serve static files automatically from a directory using `StaticFiles`.

## Use `StaticFiles`

* Import `StaticFiles`.
* "Mount" a `StaticFiles()` instance in a specific path.

```Python hl_lines="2  6"
{!../../../docs_src/static_files/tutorial001.py!}
```

!!! note "Technical Details"
    You could also use `from starlette.staticfiles import StaticFiles`.

		t.Fatalf("Number of logs want %v, got %v logs: %v", want, got, gotLogs)
	}

	for i, l := range gotLogs {
		// For each line, there should be two level string, e.g.
		// "2021-07-09T03:26:08.984951Z	debug	debug log"
		if got, want := strings.Count(l, wantLevels[i]), 2; want != got {
			t.Errorf("Number of log level string want %v, got %v", want, got)
		}
	}

Und dann ruft **FastAPI** diese Überschreibung anstelle der ursprünglichen Abhängigkeit auf.

=== "Python 3.10+"

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

=== "Python 3.9+"

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

	_ = x[HandlerReadAll-20]
	_ = x[HandlerServerVerify-21]
	_ = x[HandlerTrace-22]
	_ = x[HandlerListen-23]
	_ = x[HandlerDeleteBucketMetadata-24]
	_ = x[HandlerLoadBucketMetadata-25]
	_ = x[HandlerReloadSiteReplicationConfig-26]
	_ = x[HandlerReloadPoolMeta-27]
	_ = x[HandlerStopRebalance-28]
	_ = x[HandlerLoadRebalanceMeta-29]
	_ = x[HandlerLoadTransitionTierConfig-30]
	_ = x[HandlerDeletePolicy-31]
	_ = x[HandlerLoadPolicy-32]

    } catch (e: ClassCastException) {
      // On android 8.0, socket.connect throws a ClassCastException due to a bug
      // see https://issuetracker.google.com/issues/63649622
      if (Build.VERSION.SDK_INT == 26) {
        throw IOException("Exception in connect", e)
      } else {
        throw e
      }
    }
  }

  override fun trustManager(sslSocketFactory: SSLSocketFactory): X509TrustManager? =

Es wird nur einmal generiert und dann wird dasselbe zwischengespeicherte Schema für die nächsten Requests verwendet.

```Python hl_lines="13-14  25-26"
{!../../../docs_src/extending_openapi/tutorial001.py!}
```

### Die Methode überschreiben

Jetzt können Sie die Methode `.openapi()` durch Ihre neue Funktion ersetzen.

```Python hl_lines="29"

Hier ist eine kleine Vorschau, wie Sie Strawberry mit FastAPI integrieren können:

```Python hl_lines="3  22  25-26"
{!../../../docs_src/graphql/tutorial001.py!}
```

Weitere Informationen zu Strawberry finden Sie in der <a href="https://strawberry.rocks/" class="external-link" target="_blank">Strawberry-Dokumentation</a>.

=== "Python 3.10+ Pydantic v1"

    ```Python hl_lines="13-23"
    {!> ../../../docs_src/schema_extra_example/tutorial001_py310_pv1.py!}
    ```

=== "Python 3.8+ Pydantic v2"

    ```Python hl_lines="15-26"
    {!> ../../../docs_src/schema_extra_example/tutorial001.py!}
    ```

=== "Python 3.8+ Pydantic v1"

    ```Python hl_lines="15-25"
    {!> ../../../docs_src/schema_extra_example/tutorial001_pv1.py!}
    ```