Das ist keine Limitation von **FastAPI**, sondern Teil des HTTP-Protokolls.

///

## Optionaler Datei-Upload

Sie können eine Datei optional machen, indem Sie Standard-Typannotationen verwenden und den Defaultwert auf `None` setzen:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## `UploadFile` mit zusätzlichen Metadaten

   *
   *  - "Lax": the cookie is omitted when the subject URL is an embedded resource. It is sent for
   *    potentially-destructive navigation. This is the default value.
   *
   *  - "None": the cookie is always sent. The "Secure" attribute must also be set when setting this
   *    value.
   */
  @get:JvmName("sameSite")
  val sameSite: String?,
) {
  /**

- **MS-SMB2 Section 3.2.1.4**: Durable Open Scavenger Timer

## 3. Handle Types and Capabilities

### 3.1 Handle Types
```java
public enum HandleType {
    NONE(0),                    // No durability
    DURABLE_V1(1),              // SMB 2.1 - survives network loss
    DURABLE_V2(2),              // SMB 3.0 - with timeout
    PERSISTENT(3);              // SMB 3.0 - survives server reboot

    * `dict`의 값(value)는 `float`타입이다. (각 아이템의 가격(price))

#### `Optional`

`str`과 같이 타입을 선언할 때 `Optional`을 쓸 수도 있는데, "선택적(Optional)"이기때문에 `None`도 될 수 있습니다:

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

`Optional[str]`을 `str` 대신 쓰게 되면, 특정 값이 실제로는 `None`이 될 수도 있는데 항상 `str`이라고 가정하는 상황에서 에디터가 에러를 찾게 도와줄 수 있습니다.

#### Generic(제네릭) 타입

이 타입은 대괄호 안에 매개변수를 가지며, 종류는:

* `List`

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

### Dockerfile { #dockerfile }

Now in the same project directory create a file `Dockerfile` with:

```{ .dockerfile .annotate }
# (1)!

/**
 * @author higa
 *
 */
public class ArrayMapTest {

    /**
     * @see org.junit.rules.ExpectedException
     */
    @Rule
    public ExpectedException exception = ExpectedException.none();

    ArrayMap<String, String> map;

    /**
     * @throws Exception
     */
    @Before
    public void setUp() throws Exception {
        map = new ArrayMap<String, String>();

        return MAX_COMPRESSION_SIZE;
    }

    @Override
    public String getAlgorithmName(int algorithm) {
        switch (algorithm) {
        case COMPRESSION_NONE:
            return "None";
        case COMPRESSION_LZ77:
            return "LZ77";
        case COMPRESSION_LZ77_HUFFMAN:
            return "LZ77+Huffman";
        case COMPRESSION_LZNT1:
            return "LZNT1";

			content:    "hello",
			partNumber: "1",
			fault:      None,
			accessKey:  credentials.AccessKey,
			secretKey:  credentials.SecretKey,

			expectedAPIError: -1,
		},
		// Case where part number is invalid.
		1: {
			objectName: testObject,
			content:    "hello",
			partNumber: "9999999999999999999",
			fault:      None,
			accessKey:  credentials.AccessKey,

                    }
                    this.sids[_i].decode(_src);
                }
            }
        }
    }

    /** SID name type: none. */
    /** SID name type: none or unused. */
    public static final int SID_NAME_USE_NONE = 0;
    /** SID name type: user. */
    /** SID name type: user account. */
    public static final int SID_NAME_USER = 1;

/// note | Hinweis

Ein Pfad-Parameter ist immer erforderlich, weil er Teil des Pfads sein muss.

Sie sollten ihn daher mit `...` deklarieren, um ihn als erforderlich auszuzeichnen.

Doch selbst wenn Sie ihn mit `None` deklarieren, oder einen Defaultwert setzen, bewirkt das nichts, er bleibt immer erforderlich.

///

## Sortieren Sie die Parameter, wie Sie möchten

/// tip | Tipp