// The following code is basically called in for.
	// In order to avoid the performance problems caused by repeated compilation of regular expressions,
	// it only needs to be done once outside, so optimization is done here.
	if idx != -1 && regEnLetterAndMidline.MatchString(str[0:idx]) {
		name = str[0:idx]
	} else {
		name = rel.Schema.namer.RelationshipFKName(*rel)
	}

	constraint := Constraint{

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: Union[bool, None] = None


@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}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):

                        + "reactor to prevent race conditions. This mojo execution will be blocked "
                        + "until the aggregator mojo is done.";
                warn(msg);
                acquiredAggregatorLock.lock();
            }
            if (!acquiredProjectLock.tryLock()) {
                Thread owner = acquiredProjectLock.getOwner();

Deleting the cache when it is no longer needed can be done.  However this may delete the purpose of the cache
which is designed to persist between app restarts.

```kotlin
cache.delete()
```
 
## Pruning the Cache

Pruning the entire Cache to clear space temporarily can be done using evictAll.

```kotlin
cache.evictAll()
```

Removing individual items can be done using the urls iterator.

But if you have specified a custom response class with `None` as its media type, FastAPI will use `application/json` for any additional response that has an associated model.

///

## Combining information { #combining-information }

    )
    assert response.status_code == 200
    assert response.json() == {
        "item_id": 123,
        "name": "Foo",
        "price": 50.1,
        "description": None,
        "tax": None,
    }


def test_put_with_no_data(client: TestClient):
    response = client.put("/items/123", json={})
    assert response.status_code == 422
    assert response.json() == {
        "detail": [

</div>

Das bedeutet, dass es **immer einen Wert** hat, der Wert kann jedoch manchmal `None` sein (oder `null` in JSON).

Das bedeutet, dass Clients, die Ihre API verwenden, nicht prüfen müssen, ob der Wert vorhanden ist oder nicht. Sie können davon ausgehen, dass das Feld immer vorhanden ist. In einigen Fällen hat es jedoch nur den Defaultwert `None`.

@item_router.get("/")
def get_items(user_id: Optional[str] = None):
    if user_id is None:
        return [{"item_id": "i1", "user_id": "u1"}, {"item_id": "i2", "user_id": "u2"}]
    else:
        return [{"item_id": "i2", "user_id": user_id}]


@item_router.get("/{item_id}")
def get_item(item_id: str, user_id: Optional[str] = None):
    if user_id is None:
        return {"item_id": item_id}
    else:

/**
 * A {@link FutureTask} that also implements the {@link ListenableFuture} interface. Unlike {@code
 * FutureTask}, {@code ListenableFutureTask} does not provide an overrideable {@link
 * FutureTask#done() done()} method. For similar functionality, call {@link #addListener}.
 *
 * <p>Few users should use this class. It is intended primarily for those who are implementing an

    client = test_module.client
    response = client.get("/users/")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "message": "Hello Users!",
        "params": {"q": None, "skip": 5, "limit": 10},
    }


def test_override_in_users_with_q(test_module: ModuleType):
    client = test_module.client
    response = client.get("/users/?q=foo")