高度なシナリオでは、「キャッシュされた」値を使うのではなく、同じリクエストの各ステップ（おそらく複数回）で依存関係を呼び出す必要があることがわかっている場合、`Depens`を使用する際に、`use_cache=False`というパラメータを設定することができます。

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
    return {"fresh_value": fresh_value}
```

## まとめ

ここで使われている派手な言葉は別にして、**依存性注入** システムは非常にシンプルです。

*path operation関数*と同じように見えるただの関数です。

しかし、それでも非常に強力で、任意の深くネストされた依存関係「グラフ」（ツリー）を宣言することができます。

/// tip | 豆知識

		// If marker is *after* the last possible object from the prefix it should return an empty list.
		{"test-bucket-list-object", "Asia", "europe-object", "", 0, ListObjectsInfo{}, nil, true},
		// If the marker is *before* the first possible object from the prefix it should return the first object.
		{"test-bucket-list-object", "Asia", "A", "", 1, resultCases[4], nil, true},

    results = await some_library()
    return results
```

/// note | 참고

`async def`로 생성된 함수 내부에서만 `await`를 사용할 수 있습니다.

///

---

데이터베이스, API, 파일시스템 등과 의사소통하는 제3의 라이브러리를 사용하고, 그것이 `await`를 지원하지 않는 경우(현재 거의 모든 데이터베이스 라이브러리가 그러합니다), *경로 작동 함수*를 일반적인 `def`를 사용해 선언하십시오:

```Python hl_lines="2"
@app.get('/')
def results():
    results = some_library()
    return results
```

---

#### Credentials.basic()

The username and password parameters to `Credentials.basic()` are now non-null strings. In OkHttp
3.x, null would yield a username or password of "null".

#### HttpUrl.queryParameterValues()

The return type of `HttpUrl.queryParameterValues()` is `List<String?>`. Lists that may contain null
are uncommon and Kotlin callers may have incorrectly assigned the result to `List<String>`.


Code Cleanup
------------

				</executions>
				<configuration>
					<failOnError>false</failOnError>
					<ignored>
						<difference>
							<!-- seems to be a clirr bug that it cannot handle the different inherited 
								return types -->
							<className>**</className>
							<differenceType>7006</differenceType>
							<method>*</method>
							<from>*</from>
							<to>*</to>
						</difference>
						<difference>

print(f"Hello {name} from Python")
```

/// tip

The second argument to <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is the default value to return.

If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

///

Then you could call that Python program:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

                }
              }
            }

            else -> {
              unexpectedValues = true // Unexpected extension.
            }
          }
        }
      }

      return WebSocketExtensions(
        perMessageDeflate = compressionEnabled,
        clientMaxWindowBits = clientMaxWindowBits,
        clientNoContextTakeover = clientNoContextTakeover,

    @Inject
    private ArtifactFactory artifactFactory;

    DefaultUpdateCheckManager updateCheckManager;

    @Override
    protected String component() {
        return "updateCheckManager";
    }

    @BeforeEach
    @Override
    public void setUp() throws Exception {
        super.setUp();

    * This is comparable to using the model's `.model_dump()` method again, but it makes sure (and converts) the values to data types that can be converted to JSON, for example, `datetime` to `str`.
* Save the data to your DB.
* Return the updated model.

{* ../../docs_src/body_updates/tutorial002_py310.py hl[28:35] *}

/// tip

You can actually use this same technique with an HTTP `PUT` operation.

{* ../../docs_src/security/tutorial007_an_py39.py hl[1,12:24] *}

Isso seria parecido com:

```Python
if not (credentials.username == "stanleyjobson") or not (credentials.password == "swordfish"):
    # Return some error
    ...
```

Porém, ao utilizar o `secrets.compare_digest()`, isso estará seguro contra um tipo de ataque chamado "timing attacks" (ataques de temporização).

### Ataques de Temporização